Try Thunderbird - clean, lots of options.
I wouldn't say Mail was "broken" at this point. It works, it just works differently. Ditto for Reminders and Updates. My car from 2013 works differently than my car from 2018, but the '18 isn't "broken," just different.Why do they do that? Mail, Reminders, Updates. How many more things have they broken?
But at least they still release bug fixes fairly regularly.