Part of it I think is nostalgic and such games being seen as classics. I would offer as well in same case, that there are those gamers who look to 8-bit and 16-bit games because of how often they tended to be more difficult, wanting that challenge. Plus, simplicity in design can often be appreciated. Where because graphics isn't the selling point for these games are they are so often today. So retro games are seen a callback to when developers focused on other things.
For me its certainly require less memory, and I like the aesthetic of it, usually they are accompanied with good music.
Kinda weird for a question where this forum has a game that mostly concise of text rather than graphic.
I think a lot of it is nostalgic, but another angle I think is that a lot of people prefer (As do I) simpler times when it came to video games. There wasn’t much of an injection of divisive political issues that would take you out of the escapism of a simple game and while video games always had a profit motive, publishers and developers were a lot less greedy trying to squeeze their fans’ pockets dry as opposed to today in many cases.