Of course, you can install iTerm2 which is even better.
Thunderbird is pretty good and in my experience, less buggy than Apple Mail, especially when using providers other than iCloud. My wife absolutely hated Apple Mail, primarily because it would forget passwords and stop syncing/sending. So I moved her to Thunderbird and now she's happy.
Half the time I miss-click the first email and sort by subject. In what world would I want to sort my emails by subject!?
Search vs. filter messages, I really don't need two search bars, one is fine.
I'm annoyed that the default sort is oldest to newest, and that I have to change it for each individual folder.
Tabs really don't fit into how I consume my email. Flagging important ones is good enough.
I'd take Geary (https://wiki.gnome.org/Apps/Geary) over Thunderbird any day, but lack of GPG integration is what's forcing me to stick to Thunderbird.
The sad fact is that there is simply no money in building email clients. Email is a legacy technology and arguably no longer fit for purpose. We need a new standard and that's not something that BigTech has delivered yet.