nextcloud tries to do everything so it settles for good enough instead of doing some things really well. the text part of chat works well, its webrtc struggled for me even with the high performance backend. i set up a jitsi server with only jwt auth going through the nextcloud integration on mine to get around that limitation.

there is a guest join by link feature in talk. though nextcloud can also be set up to use outside oidc. so you could allow people to log in with their existing accounts. making it easier for people who would struggle registering.

nextcloud will lower the barrier for entry on your users with the ‘single interface’ feel. its just gonna shift that effort onto you to scale past like 10 users.