I loved the hell out of BG2 - probably spent far too much time playing it as a child. But even back then, there were tons of issues I had with the game's choo-choo-train narrative. So much of the story is forced, and player agency is constantly denied at every turn, in BG2.
The below is just the base game, and none of the absolutely dreadful content Beamdog added in their EE.
- The initial premise is hinged on you caring enough about Imoen to go after her. She died in BG1? Don't worry about it. She's also invincible in the initial dungeon. This is especially bad because they replaced this motivation with something far more personal mid-game. They could've actually just used that in the start. Instead, the story goes on a pointless loop.
- There was no "do it on your own" way into Spellhold - you had to work with 1 of 2 shady factions and do a bunch of predictable, boring quests for them, which drove me crazy even when I was a kid. No playing them against each other either.
- Per the above - try to kill one of the Chapter 3 faction leaders you've aligned with? An invincible enemy with a one-hit-kill attack spawns and just ends you game. Equivalent to a DM saying "don't like my railroad? die". It's worst than Bethesda's invincible NPCs IMO. Why send the bhaalspawn to do the dumb quests when they had this guy under their disposal? Btw, these guys don't spawn when you attack the faction leaders under the quest line. They exist only for Bioware to say "FU" to the player.
- You cannot do anything to prevent being captured* during the Spellhold sequence (auto negative in any RPG IMO) - even if you can see it a mile away. Bodhi acting sketchy AF? Just gotta play your part in the story and derp your way forward.
- Going back to my first point though - getting captured is extra salt in the wound because the game hits you with leaps of logic/railroading just to land you right back where you started. Oh, and then you get the "villain fails to kill you by playing games instead of finishing you off" trope to keep the story going.
- Outside of the "gather 20,000 gp" in the start of Chapter 2, the game never works to give you reason to do side-quests. In Chapter 2, once you had the money, your motivation should be to get to Spellhold asap (if you buy the whole "save Imoen" thing). In Chapter 6, you're soulless and in pursuit of Irenicus - contradicts the need to do side quests at all (but it's the only other open-world section).
One thing that Larian has demonstrated with BG3 and DOS2, is their commitment to player freedom. The game is always carefully designed so if you can spurn almost everyone, and can still progress somehow. It's very similar to Fallout New Vegas with their yes man option.
* P.S. - old school Bioware had some intense cutscene-incompetence + capture fetish that they HAD to put in almost every game.
BG 2 - Spellhold
Kotor - Leviathan Sequence
Dragon Age Origins (sort of) - Ser Cauthrien (unbalanced, but at least you
can fight your way out of this one, although you lose XP for not being captured)
Dragon Age Awakening - Silverite Mine