I am eternally skeptical of the argument of old games being better and modern fans being dumber/inferior in some way. I think that the latter argument is always untrue, though the former argument is usually untrue but can vary game to game.
There is some validity to the claims, however only to certain extents.
"Old games were better" has the truth of "Old games were generally more complete when released" - Back when you couldn't just ship patches out the wazoo (Also back when gaming was more niche so it was more gamers making games for gamers and fewer corporates making games for shareholders) there was more emphasis on making a polished, functional product out of the gate. While most modern games aren't finished until a year after their release (If they finish at all).
"Modern fans being dumber/inferior" has the truth of games being more mainstream, so you get more casual gamers. You have things like whales funding terrible MTX practices, you have kids eating up slop like CoD, FIFA and Ubisoft games that are churned out using copy/paste as well as game "Journalist" types that cry whenever a game doesn't hold their hand through the entire experience...
These aren't end-all-be-all terms though. There are plenty of games being released that are well polished on release, that are designed for gamers and not shareholders. There are still hardcore gamers that want good games that don't hold their hand all the time.
As for complaints about too much reading and the game being hard
Most of these complaints are actually results of old games being old. Thus having limited technology and software to actually implement things well.
Heavy reading reliance because having fully VA dialogue was too much back in the day. With a lot of difficulty being due to janky controls or systems.
As far as UI is concerned, older games can certainly have good UI, I've not played any of those games with the original UI to judge, but just because it worked for people doesn't mean automatically that it's objectively good.
Honestly, as someone who's recently been on a binge of older games... Most older games UI's are actually trash. Like, they're serviceable, and certainly were great at the time, but compared to most modern games the UI just sucks.
I haven't recently replayed BG1 or BG2 though so can't comment specifically on those. But overall my experience of older games is usually awful UI, janky controls and dated systems (With the games that hold up today being those that have great writing. Something that is lacking in many modern games in favour of shiny graphics).
Which is probably why RPG's are often the highly rated classic games, as people remember the story of games like Planescape: Torment, FFVII, System Shock, Fallout 2, KotoR etc despite their gameplay being nothing spectacular.
