I really like remmina use it daily for work. Tabby is interesting but too heavy imho

This is the closest I’ve found.

https://flathub.org/apps/com.github.muriloventuroso.easyssh

Edit: then again I primary used mobaxterm for SSHing into all my servers.

I use "terminator" -- it has a different visual appearance, but does a lot of the same features, and some I think better. For instance split screen in various ways, and input multiplexed and sent to multiple tabs / screens.

Cross-linked c/linux terminal emulator discussion

I don't have any solutions but I'm interested in an alternative too.

i use https://remmina.org/ for managing rdp and ssh connections

I just use any basic/default terminal. For SSH I prefer to automate tasks like entering passwords, proxying/port forwarding, jumping over gateway servers, ... using shell scripts.

Try Ásbrú Connection Manager for multi-tab SSH. The only thing missing for me was integrated SFTP.