Parroting is really the extent of it.
Rangers are easily as good in combat as fighters are. Folks talk as though Fighters have some huge advantage because a pure fighter at level 11 gets an extra attack, but in reality the most effective combat builds are not taking 11 levels of fighter. Monk/Warlock/Barbarian Tavern Brawler shenanigans can get you 50+ damage per attack and 6+ attacks per turn if all you care about is dishing out damage, while moving quite fast. But because folks are convinced Champion Fighter is the king of damage, if it doesn't get that 3rd attack at level 11 it's dismissed as a 'subpar fighter'.
Rangers get an extra attack at level 3, whether that's via Horde Breaker or Dread Ambusher or best of all a companion, and they retain an attack advantage vs a Fighter from level 3 all the way through to level 11. At level 11, it's debatable, because while the Fighter catches up and indeed pulls ahead while using Haste, Beast Master Rangers actually get an extra attack on their companion, pushing them ahead again. If you ignore the companion's unique abilities and attacks and assume the Champion Fighter is always under the effects of haste and theory craft scenarios in your head where the Champion Fighter has an advantage, then sure, Champion Fighter will still pull ahead damage wise. But in practice Rangers will do just as good if not better, through every stage of the game, vs an equivalent fighter.
Their unique features are also not at all environment dependent in BG3, granting things like Proficiency in Heavy Armor (meaning that while a dip in Fighter after level 1 won't grant heavy armor proficiency, Ranger will). Hide in Plain Sight in BG3 only takes an action instead of a minute. They have spells, they have better skill proficiencies, they are a perfectly functional and capable class. But folks hear they're bad so they avoid them and parrot them being bad to others, without ever trying them out themselves.
I've never been in a PnP campaign with a Ranger where they didn't shine, in my current campaign we have both a Ranger and a Fighter and the Ranger does easily 3x the damage the fighter does. Part of that is due to the Ranger being, well, Ranged while the Fighter is melee, so the Fighter wastes more actions and turns trying to get to enemies while the Ranger just keeps pumping out damage, part of that is due to the Ranger having Sharpshooter while the Fighter is Dual Wielding rather than going Great Weapon Master, and Sharpshooter and Great Weapon Master are outright busted from a balance perspective, and part of that is (I suspect) due to the Ranger cheating a bit, assuming they have advantage and are not seen by the enemies when the DM hasn't confirmed it, or deciding to apply Sharpshooter after rolling, or reporting to hit numbers consistently that would imply the penalty for Sharpshooter was not taken while reporting damage figures which would imply it should have been, all the normal stuff which tends to happen in PnP campaigns when Sharpshooter or Great Weapon Master are around. Even setting that stuff aside though the Ranger would easily exceed the fighter's damage totals, largely because Fighters don't actually have that much of their kit which improves their damage output vs other Martial characters, beyond the one round per rest action surge.
In BG3, Rangers are even better than they are in PnP. I'm glad you're having a great time with them, they're a great class. I wouldn't worry about those who knock the class based on blanket unfounded assertions or 'white room analysis' (theoretical scenarios cherry picked to prove a point). I certainly haven't heard anyone in BG3 or PnP who has ever actually *played* a Ranger and said 'Man I just can't keep up in terms of damage output' or 'I never feel like I'm useful and contributing to the party' or anything of the sort. Nor do I expect I ever will.
