Counterexample: Thunderbird. I recently tried TB based clients, and then TB directly to see if it already has those issues. And it turns out, it does. Interacting feels sluggish (not on a resource constrained device, Win 11, 32 GB RAM, Ryzen 5 3600).
Now Outlook (which I use for work and was the reason I wanted to get a unified client for everything) is a bit faster than the MS web interface (or the horribly slow Gmail one), but the fastmail interface is faster than all of those.
Though Outlook is an exception. It has always been...garbage in my experience. Crashes, incredible lag, addons that fail to load, etc. I consider it a miracle if I get through a day with it all working properly.
My encryption settings are constantly being reset so I have to enter them almost EVERY SINGLE TIME, which is lovely.
What webmail?
> Crashes, incredible lag, addons that fail to laod, etc.
Maybe those addons are the issue? I’ve never had lag, and crashes are < 0.5/year. But I also have zero addons.
It's nice to have a dedicated piece of software that I know works and I don't have to worry that some weird browser issue or one of several dozen addons isn't causing a problem.
I mean, Thunderbird is really just FF under the hood from what I understand, but still.