Thunderbird of now is more annoying and less convenient to use than when I last time used it in 2010's, before I moved to claws-mail.

And only reason using it now is cos of MS fucked up oauth2 method that is PITA to setup for any other OSS client as it requires the app to be added to their catalog and only thunderbird was big enough to get that

So I can understand the annoyance

To be honest while I’m not the biggest fan of Thunderbird I struggle to understand how this is true by any measure.

The program is pretty much the same as it was in 2010 from a UI standpoint.

My biggest complaints with it are that the profile configuration is not portable, and that the UI is too cluttered with features. I just want something simple that does all the important stuff and remains somewhat powerful.