Yeah, I've defaulted to scp, rsync, sshfs, and samba for my own use. When I need to send files to other people, I either scp them to a public dir on my HTTP ser

Yeah, I've defaulted to scp, rsync, sshfs, and samba for my own use. When I need to send files to other people, I either scp them to a public dir on my HTTP server and send a link or I use one a centralized service (e.g. slack or the ones you mentioned). This solution is not really available to non-technical people, but it works pretty well for me.