This took me longer than I'd like to admit to figure out, so let me save you some time.
Community size matters more than people think. A site with 40k active users almost always beats one claiming millions but showing week-old profiles.
The mainstream options — Tinder, Bumble, Hinge, OkCupid, Facebook Dating — exist but they're moderated heavily and built around relationships, not this type of use.
Places like souldate.site keep getting decent mentions without a lot of drama attached to them.
Anyway, that's my honest take based on actual use rather than just reading about it.