All seems like an exaggeration.

There was so much shit that wasn't known in beta. Like tons of stuff, especially around mechanics etc. The stuff that was discovered during beta changed in some cases at launch as well. The stuff that was discovered and didn't change wasn't extremely widely known because the internet resources just weren't out there as much upon launch.

With a smaller player base, and harder to find the spoiler. Doesn't take away that spoilers could be found if you cared or looked for them, even in closed beta's with nda's. Or the fact content is spoiled the day of release, for anyone coming to the game after.

Having a small handful of people in a 20+ year old game, rushing items and money.
Doesn't take away that the same thing happens 5-10-15-20 years later, by more people in expansions or other games with larger player base.

People have rose tinted glasses, if you think this didn't happen before.

Think you missed the overall point. The point wasn't that there were a very small number of players who knew some drops or leveling locations (although they didn't know all of them obviously). The point is that like 95%+ of the players (even a ton that participated in beta because a lot didn't progress hugely far during the beta) didn't know very much at all, and the internet resources weren't really there, so the game was basically a fresh launch with very minimal knowledge for everyone and therefore it was an enjoyable experience.

Who cares that random person A knew about JBoots or manastones for example. At launch in 1999 the world was new, unknown, and mostly unexplored even for a lot of people who played in the Beta.

There is so much stuff on p99 that isn’t documented nor public knowledge (or went under the radar for a decade). Those are p99 exclusive mechanics, but I have no doubt live had equivalent undiscovered jank.