I don’t know about good, I haven’t tested any of them yet. But from my “list to check out” that is not the already mentioned jitsi (I’m mostly focusing on self-hosting but some of those have public/hosted plans too):

• https://movim.eu/
• https://lasuite.numerique.gouv.fr/produits/visio
• https://opentalk.eu/en/open-source-code-und-community
• https://nerimity.com/ (I think that one is GB)

Both FOSS and European or just one or the other?

I would prioritize FOSS software over software made from a specific region in the world.

Doesn’t Matrix support video/voice calling?