Bill Zebub
“It’s probably Matt Mercer’s fault.”
What it really comes down to are the philosophical & ideological differences. 2e was the beginning of the end when it came to DM control. The focus began to shift to empowering the poor, disenfranchised players, or "player agency" as it was eventually called. The second was the absence of all of those DM resources (tables, generation charts, detailed clarifications, etc.) that you say that no one even used. TBF, I come from that magical time period when all that my mentor DM had were the LBBs (+supplements), the MM(1) (finally!), the CSotIO setting, and a WHOLE lot of homebrew charts and milieu data (mostly based on Tolkien's works). We were so excited when we managed to acquire a copy of the new PH and, eventually, the DMG. We were in absolute heaven! The DM was Lord of the Manor back then, and we loved every second of every session....even when we suffered horrible fates, by the capricious fate of the dice, the stupidity and/or arrogance of character action/inaction, or () having the actual temerity (as a player) to disrespect the DM. This is how it should be. This is what we lost.
Boy, the way Glen Miller played....
(EDIT: I mean, I'm nostalgic for those early days of RPGing, too, which is why I play Shadowdark. But I manage to do so without a litany of grievances.)