If you allow stretching budget slightly (as the article does), B570 reduces the number of compromises that an A750 makes (though of course there's still some).

Second-hand market is pretty serviceable at the price point too. I don't know how the demographics for these preferences slice up, but I basically don't play any new AAA games at release - so honestly 8GB is almost always enough for me, which makes a lot more second-hand cards viable (though I would still be hesitant to buy a new card with 8GB unless it was on a killer sale). There are surely a non-trivial number of people who also mostly buy several-year-old games on sales instead of new releases who don't need the extra VRAM to still have a perfectly playable experience.

edit: typo