I know this comes up but I haven't found a thread with recent enough information to be useful.
Niche-based matching has gotten genuinely more sophisticated. The question is whether the dedicated niche platforms have enough user density to be worth the smaller pool, or whether using the interest-filtering tools on mainstream apps gives you better practical results. The answer varies a lot by location and specific niche.
Language skills and cultural openness as explicit profile fields are available on the better international platforms.
Would really appreciate honest takes from people with genuine experience rather than what the platforms say about themselves.