I have a Nextcloud for my own, works mostly well, but it requires some effort here and there and I oft wondered what my dear users would say (if there were any) if it takes me several days again to fix some small issues or renew the certificate. Plus I know nothing about security and can only hope everything is all right. Once you set email, messenger etc. up for larger groups I could see the efforts to keep this stable and secure to be quite high. It’s probably a good solution for the privacy problem but I am not so sure that it is a solution that is manageable or even available for many and therefore a good solution overall.