I'm not in YNAB's target market either, but the value they provide is useful even if you're not struggling month to month with finances. You get really good control over your money and a much better understanding of how you're spending it and where.
Being really aware of that makes it easier to actually leverage it more because you know exactly what you can put where so you can be closer to zero in your checking account (push more towards investments, etc.).
It also makes it easier to change behavior and know exactly what knobs you can turn with your finances.
Only downside with it is that the auto-import sucks (I suspect because the bank APIs suck). I move all transactions through one credit card and I manually create transactions in YNAB when the card is charged. I use the Apple Card which has really good software so it's easy to notice transactions and make sure things line up.
My username is also from when I was 13 and really excited about linux :-), now mostly on macOS - I haven't really lived up to it.