I want to say Alacritty+zellij but have not even tried that lol.
Konsole. It just works, has profiles etc. I highly recommend to change it to "launch every window in same process" to avoid multiple windows, create a new desktop entry replacing "konsole" with "konsole --new-tab".
And also learn Desktop actions, its very cool!
I have a profile with different colors that starts in my Distrobox.
my example desktop entry
[Desktop Entry]
Type=Application
TryExec=konsole
Exec=konsole --new-tab
Icon=utilities-terminal
Categories=System;TerminalEmulator;
Actions=FedoraBox;root;ssh;
X-DocPath=konsole/index.html
X-DBUS-StartupType=Unique
X-KDE-AuthorizeAction=shell_access
X-KDE-Shortcuts=Ctrl+Alt+T
StartupWMClass=konsole
Keywords=terminal;console;script;run;execute;command;command-line;commandline;cli;bash;sh;shell;zsh;cmd;command prompt
Name=Konsole
GenericName=Terminal
Comment=Command line access
[Desktop Action FedoraBox]
Name=Distrobox
Icon=fedora-logo-icon
Exec=konsole --profile Fedora-Box
[Desktop Action root]
Name=root Terminal
Icon=folder-root-symbolic
Exec=konsole -e pkexec $SHELL #or define a shell
[Desktop Action ssh]
Name=ssh to X
Icon=folder-remote-symbolic
Exec=konsole -e ssh user@IP:PORT -i /path/to/key
Plasma will still display "open new window" which will instead open a new tab. Pressing Ctrl+Alt+t will also open a new tab, just as opening from Dolphin etc. Perfection!
Note that Konsole will pull in tons of dependencies, you may want to use XFCEs Terminal if you dont want that. Alacritty has no tabs which I find annoying (I hate windows).