Like all things of that era, any comment about 'how we all played' is innately mistaken. However, 'how we all played' in my social circles was that -- for both 1E and 2E -- we used what we wanted, discarded what we didn't, borrowed heavily from BX/BECM where preferred, and generally made the game what we wanted it to be. If I were to play either of them today, it would be a lot of BX core mechanics with some vital AD&D components (like spell disruption), and the 1E or 2E class descriptions, monster listings, weapon charts, etc.
And I think that's what people do. Many by playing one of the many (many... many) osr games out there that are usually ostensibly modelled after one or the other, but in reality at least partially
'the way we played TSR-era A/D&D, but with...'. Others by playing their old copies of one of the different main games, but like my first paragraph being a wild smear of all of them as one sees fit, along with house rules up and and down the play experience.
1e is painful by comparison. Again, I say this as a fan! But let's be real.
So here is my take -- 1e, 2e, and oD&D-RC are
all painful in various ways, and I say that as a fan (of each). Thieves are garbage in all of them -- sure some of them have worse percentages, but that's minor compared to fundamental issues like those 7 tasks being a static list, their relative adventure contribution dropping off as you level, and you being systematically ill prepared (highly fragile) to handle the fail state of many of them. All of the systems have lots of tables that could slow the table down (2e coming in in 2nd place, honestly). Bards (and monks/mystics, and multiclassing) are not greatly integrated into the game, and end up being wildly swingy based on what other rules you use. Skill systems (NWPs from 1.5 or 2e, or the BECM/RC version) are all fun for building character theme, but are poorly integrated with the rest of the game. Psionics in all the different editions are wildly overly complicated, and as much as I value anyone saying they find them an important part of their D&D game, I generally think that some other (homebrew) system works better than any of the official rules of the TSR era.
And yet, we see a lot of 1e clones, but IIRC, there's only one 2e clone, and almost every single OSR group I've seen plays a 1e version and not 2e. Does it really come down to "Gary's edition vs. Lorraine's edition?" Or I'm hoping it's more for nostalgia and the memories.
If we're talking about OSR published games, I honestly find BX to be the backbone of more games than any other of the TSR editions (probably because it is easiest to pull back to bare studs). When people pull out the old books and start playing, yeah I agree most people grab the 1e books. But again, as stated above I think usually what they are actually playing is their own house rules which use the parts of all of them that they find engaging (or at least worth the effort).
AD&D 2e starts as a well defined core with Zeb Cook's books. But it immediately goes off the rails with over a dozen "Complete ____" books, and continued with supplements like the Arms and Equipment Guide, multiple monster manuals, and multiple rules expantions. The number of settings is just bonkers, with lots of creativity but also lots of overlap. The number of rules that a re-written multiple times is extreme. I was at a con panel once where one of the 3e designers mentioned that they found 6 completely different sets of drowning rules publised by TSR in different 2e books.
The result of the above is that there really is much of a less defined zeitgeist for exactly what "2e" means. Different groups at different times have completely different ideas of what the rules are, what the baseline of the system is, and what "D&D" means in terms of setting and flavor.
This is another great thing to highlight. A huge amount of the things that 2e brought are ideas moreso than hard rules. I know a lot of people that capital-L Love the ideas surrounding kits and specialty priests and playing as swashbucklers or pirates or defining your character through NWP selection. But at the end of the day, a lot of the rules actually printed vary wildly in playability and balance. Those that want to explore those things generally will do so with their own heavy re-build. In which case any system is as good as another, since you'll be rebuilding to suit your own needs anyways.