@Edent@mastodon.social not a matrix user myself and can't say
#xmpp will impress you, but there's definitely not a centralization of ownership issues. Most of that community seems to be rallied behind
#snikket lately which I self-host with delight thus far. Fragmentation in feature support across clients is the biggest struggle currently. More niche, but I do funnel my WhatsApp and Mattermost messaging through my XMPP server using
#slidge. Been very stable for WA, have to restart Mattermost gateway regularly.