I totally get your problem, shonen stuff just gets promoted the most because it sells best. But there's definitely a lot better stuff out there, you just have to search more deliberately.
Check out genres on sites like MyAnimeList and filter by character development or psychological - you'll find real gems that don't land in the mainstream charts. Smaller studios often make insanely good stuff too, it just gets less hype. If you want something dark, psychological thrillers or dark fantasy series are usually your best bet, because most shonen fans aren't interested in those anyway and they don't get pushed everywhere as much.
Practical tip: look at the "staff picks" or "critically acclaimed" lists on anime forums instead of YouTube trends. The algorithms just show you whatever's going viral right now, but in smaller communities you'll find people who actually collect and discuss deep character studies or story-heavy stuff. Older series that got overlooked back then often have way better stories than some new mainstream thing - you don't have to limit yourself to 2026, you can also look at stuff from a few years back.