Might be a dumb question about the best platform, but I'd rather ask than guess.
The the best platform thing nobody mentions is how much timezone and schedule overlap matters. Nobody gets the best platform for international right first time and the people who claim otherwise are lying.
For the best platform, keep socials private until the conversation has run a few days. Separate email and location permissions off, then worry about the best platform.
Most the best platform for international complaints I see trace back to an incomplete profile.
Nobody warns you that the best platform for international is mostly patience and a decent second photo.
eHarmony
Match.com
EliteSingles
Zoosk
Plenty of Fish
OurTime