Contrary to the unending false impression tech sites give out, many people don't buy bottom tier GPU's to run AAA games badly, they buy them to run the bulk of the +30,000 Indie / middleware / older titles on Steam, GOG, etc (which typically use a lot less VRAM) at an affordable price. I own a GTX 1660 (6GB) but 95% of games I run (plus
those on the top 100 games people are consistently playing) are under 4GB, and most Indie's in 2021 haven't actually got much "VRAM thirstier" than those from 2014-2015.
It also doesn't hurt to have at least one 4GB VRAM card on the market whose "too low VRAM" also makes it undesirable for miners for the many people who run above-mentioned lighter weight games and actually want the card in stock...