What characteristics of a game do users like? ....What makes a game more popular than other games?
I'm purely a hobbyist so this is a gut feeling, but these two questions I suspect have a much bigger divide than appears at face value. What I mean by that is there are plenty of immensely popular games riddled with characteristics I suspect most users DON'T like.
In my eyes, most 'successful' (and by association popular) games today include:
Gambling mechanics,
pay to win (even in single-player games),
paywalled content,
slow/convoluted matchmaking,
planned obsolescence,
re-used mechanics,
grind,
bugs,
poor portability/cross-play compatibility
etc.
However, most of the above are largely why AAA studios are obscenely rich, and therefore like lightbulb cartels of old, the users are forced to accept 'that's how it is'.
Ultimately I think these days popularity of a game is largely luck, gross amounts of marketing/lying or pre-existing IP. Some pre-existing IP also originally started with luck as they may have simply released something first (for example particularly older series which may have defined a genre or benefitted from a step-change in technological advancements).
####So if what users like /= popularity, why make games that users like?
In my opinion, if you are a hobbiest indie dev I'd say don't. Make games that YOU like, and then maybe sequels based on fan reactions/feedback.
If your aim is to be a career indie dev/small studio startup that actually needs to make money... well some of those mechanics that users don't like.... there's a good chance you may end up adopting one or more of these as time goes on.
Sadly I think Stardew Valley/Undertale etc. are the exception, not the rule :(