If each note sounds good, it is good.
However, if the strings have worn visually obvious low points in the frets (might be on just one or two), well, then you can literally see that a problem is developing (even if it isn’t yet an actual problem when playing the instrument). Nevertheless, like i said, if it still sounds good, then it’s still good.
You can get a "level and crown" to get the frets all even (leveled) and well-shaped along the tops (crowned) again, but now the frets will be overall less tall (which might be fine, especially for a first level ‘n crown done in a timely manner). Eventually fret wear will crop up again if you keep usiing the instrument in a similar manner, and you can probably get a new level ’n crown. ‘Eventually eventually’ though, the lowest divot will be too low for a level and crown to leave you with sufficient fret height and the frets will have to be replaced (or you could get an entire new neck, I suppose).
For reference, I’ve been playing guitar and later bass for about 35 years now and in that time have had two level ‘n crowns done. Never had a refret. That said, I haven’t owned one guitar that long (my longest owned currently are about 14 years for one of my guitars and 12 years for one of my basses), and now I have a number of each and divide my playing time between them. My most played (and longest owned) guitar is one of the two that I had a level ‘n crown done on, and it’s definitely showing significant fret wear again 12 years later. It’s a bound neck, so it’s "bound to be" a problem eventually (so to speak).
Basswise, I’ve got 5 basses that I divide my playing time between (though I mostly just play 2 of them), and besides the 12 year old one, the others are all only a few years old each, so, in terms of fret wear, so far so good. The bigger problem is, unfortunately, "me wear"! I think I’m gonna wear down before I’ll have to do anything more than a level and crown to any of my basses. If you have an older instrument or play hard using thick steel strings all the time on just one instrument, your mileage will likely vary