https://wiki.alcidesfonseca.com/blog/online-boardgames-platf...
Boardgamearena and yucata have the largest collection and the best user interface in 2D. Tabletopia and tabletopsimulator are 3D and (mostly) paid.
I have played some Steam games which support Remote Play Together (sharing screen and inputs from one device), so only one player needs to buy the game.