Evolution looks neat but for me a huge problem is the lack of crossplatform-ness. I use windows as my main desktop OS simply because I like to play a lot of games in my free time, but at the same time I use Linux for development (at work and at home), thus it's quite important that I can use certain programms on both machines.
Thunderbird seems like the only cross-platform open-source mailcient that that is at least somewhat alive.
I tried moving off thunderbird to just about every graphical open source client I could find but they were all missing some key threading functionality that I use heavily. Particularly either 1. Show the discussion tree in my inbox and 2. Pull up the entire thread for a message in my inbox (or search or any other folder).
I've stuck with Thunderbird because it doesn't have an major flaws. But it is definitely slow and clunky.
I was a Thunderbird user for maybe 15 years. Switched to Evolution, imported Thunderbird and was happy from day one. No issues.
Sorry that you are using Nvidia and therefore have Wayland issues. Using Wayland since 2 years and ditto no issues.
It doesn't work on Wayland for me, but that seems to be a general WebKitGTK bug and might be related to something Ubuntu- or NVidia-specific.