tl;dr: If 2E books were still in original printing quality, I'd still be buying those to this day. That was a fantastic collection, with plenty of resources for extremely high-quality games, without getting grossly overcomplicated by 395 base classes and 1,125 prestige classes of 3rd Edition.
This may just be two cents from an old Grognard, but I have to say, I'm really disappointed by the support this movement gets. How millions of people can spend hundreds and hundreds of dollars on a tiny handful of 5E books, then turn around and amicably start all over again just blows my mind.
I must not be made of money like everyone around me or something.
5E doesn't have even half of the number of sourcebooks and reference materials of 1e, 2E, and especially not 3E, but here we are. Everyone's spent twice the cost per book for 5E stuff, many paying double that because of physical plus digital copies, only to now start brand new with this essentially 6E stuff even though 5E is really still in its infancy, despite being 10 years old now.
It's even worse for online players and DMs. They wasted a veritable fortune— the equivalence of car and/or mortgage payments! —on stuff which will now be outdated and useless. How do they not see DnDBeyond/5E/et al now has a future of being discontinued, then fully unsupported, and finally completely inaccessible at all anymore online.
All because players gave in to the corporate greed and got suckered into 6E. 5E itself has already felt the fracture, with big names like Kobold Press abandoning D&D to make their own (arguably: terribly and cringey-named) RPG.
And just like 3.x, the new 5.whateverthehell books, adventures, and resources are going to confuse relatively new players and DMs, who won't know what goes with what.