In general, fewer, although I think 5e may have gone a little too far. I like Level Up's addition of "Culture" for knowing about what various peoples are like, for example. I think a good rule of thumb is that you don't want to split up a relatively simple activity into multiple different skills. If you're trying to avoid being noticed, it's better to have a single Stealth skill rather than separate Hide and Move Silently, both because it's really rare that you'd do one without the other, and because Stealth can also cover other senses. If you're trying to get by in the wilderness, it's better with a single Survival skill than also having Hunting, Fishing, Make Shelter, Make fire, Foraging, and so on. Hunting and Fishing being different might be realistic, but it's not really fun.
It also depends on what sort of game it is. A class-based game can manage with fewer skills than a skill-based game, because a lot of the things that would be skills can instead be baked into class stuff (like fighting ability or spellcasting). But in general I like fewer skills, but with abilities that either enhance particular uses of skills, or allow you to use skills in novel ways (e.g. Pathfinder 2's skill feats).
As an example of an entirely skill-based game that I think has a pretty good skill list for a modern-ish game (60s), I'd use Troubleshooters with its list of 28 skills. These include some things that in D&D are ability scores or adjacent to them, like Agility, Strength, or Willpower. You also have some things that aren't really learned but still work the same way, like Credit or Contacts. In addition to these 28 skills, there's also a set of binary abilities that you can use for more differentiation – both the race car driver and the pilot has good Vehicles skills, but one has the Born Behind the Wheel ability and the other has Pilot (and maybe even Fighter Pilot).
