First, let me say that I'm not disputing the effectiveness of monks. I particularly like the class.
But in fairness, I'd make a few points:
1. Savage Attacker is better than implied, especially because the great weapon fighting style does not reroll ones and twos perpetually. It is a one time reroll, which is substantially helped by savage attacker, especially when additional dice begin piling up.
2. Precision attack and evasive footwork have to be considered more fully. As well as riposte. Short rests are not exactly hard to come by.
3. The comparison offered is based on the use of strength potions which is naturally going to favor the monk with the tavern brawler feat. The monk, without respec, simply doesn't have the point spread. This causes a heavy reliance on elixirs and potentially slot items that aren't necessarily needed by the fighter. For instance, while the monk needs either a respec or an elixir to make effective use of tavern brawler, the fighter could be using an elixir of bloodlust, granting even more actions.
1. Your point about great weapon fighting not rerolling ones or twos perpetually is accurate and fair. But I disagree with its characterization as "substantial". It took me longer than I would've liked to go ahead and get the AnyDice comparisons built to get the actual numbers, but here you go:
https://anydice.com/program/3214aThe "GWF" is Great Weapon Fighting; "Savage" is with Savage Attacker, "Both" is with Both, of course. This is all for the 2d6 from a Greatsword, of course. What I had been saying earlier about it getting worse, not better with a reroll holds true - the difference is not as substantial because the reroll is better, but inherently less dice variance leads to less impact. GWF already gives you an average of 8.33, almost the same impact as Savage which on its own is 8.37. Both of them boost the average damage by close to 1.4. Combined they average 9.46, which is to say, adding the second of them boosts it by roughly 1.1 damage, 1.13 to be specific if adding Savage attacker to someone using Great Weapon Fighting. That's numerically less of a boost, and fairly significantly less of a percentage boost.
Now, please don't misunderstand - I'm not saying Savage Attacker is trash tier. Adding an extra point of damage or two on average is never a bad thing. The Caustic Ring is *awesome* for adding +2 damage to all attacks. But it's certainly not "S" tier. It will add 1 to 3 damage to each attack on average, with 3 being a pretty generous number and a fairly unobtainable target for it. It's nice though in that it feels good - with both you're getting at least a 7 96% of the time instead of 81% without, so that's 15% of the time you would have gotten less than a 7 but got at least a 7 instead. You double the percentage of time you get a 12- from 5% to 10%. If someone likes it, I'm not at all saying they're wrong for liking it.
The issue I had was with it being described as "S" tier, as a small bonus to damage per hit is never as good as a boost to how often you can hit, outside of very low initial damage figures. Getting a consistent bonus action attack (like from Polearm Master if using that weapon type), or being able to consistently use your reaction to attack (like from Sentinel), or being able to turn a miss into a hit in a desperate situation (like from Lucky) adds 30+ damage to a well built character's damage output. That means that *best case* it's the equivalent of Savage Attacker improving 10 attacks, and it's rarely that good for Savage Attacker. After all, the +3 damage only matters *at all* if it *actively reduces the number of hits or actions needed to kill the target*. In most encounters, you're not actually comparing against 400+ HP bosses where it's a 1:1 comparison. Instead, you're comparing against targets of variable health, and going from 30 to 33 damage doesn't actually impact anything at all if you're attacking a target with 50 health. It's still 2 attacks to take them down regardless.
Now, the increased consistency is nice in that regard, and there's few worse feelings than a target being 2 HP away from death, whether that's in reducing them to 0 or the threshold for triggering Cull the Weak. But the amount of times it'll be the difference maker and provide that critical last 2 HP is exceedingly unlikely to match or surpass the value provided by something like GWM, Sharpshooter, Lucky, Polearm Master, Sentinel, Spell Sniper, or Elemental Adept, to say nothing of Tavern Brawler. So yeah, imho solidly a "B" to "C" tier feat, one where there are certainly builds that will take it, and you're unlikely to regret taking it if you do. But not "S" tier, not even close. Maybe I'll make a post for folks to rank feats, we can see where it lines up in the rankings of others.
I'd dive into 2 but this is already a long post. I agree it's worth diving into, I'm just not prepared to do so at this time.
3 though, I just want to say, we're already assuming 12th level (since if comparing at say 5th level, or 7th level, or basically any point in the game before 11th level the Monk absolutely smokes the Fighter in terms of performance). We're assuming a boss where it never moves and both of them start 0m away from it (since if we were to worry about positioning, the Monk would smoke the performance of the fighter). We're using something with a single health pool so we don't have to worry about the Fighter losing damage to overkill (since it doesn't matter if your attack action does 1 attack or 3 if the enemy has 10hp), and we're using the most effective potion the fighter has access to in that circumstance, something which everyone can have limitless amounts of with a bit of patience and a good Rogue. Is it *the very best case* for the comparison from the Fighter's perspective? No, of course not, and certainly there are times where a Bloodlust potion is better, based on the confluence of circumstances, and there will certainly of course be times where a fighter would outperform a Monk in a given scenario and against a given set of enemies. But imho this is pretty darn close to best case, and *far* more slanted in favor of the Fighter than the Monk. The entire point was and is that Monks are not trash and are not bottom of the barrel in comparison to other Martials, they are in fact likely the strongest of them overall. That doesn't mean Monks > Fighters in all ways and in all circumstances of course, but the circumstances where a Monk outperforms a Fighter are in my opinion substantially more common than the circumstances where a Fighter would outperform a Monk, including but not limited to during boss fights.
