Years later, kmail still is not a viable email client?

[dragon at peerfreedom.org]

Long time ago I  was using kmail, until it become slow and buggy.
Many would say that Akonadi was too blame.

Now after years I again try to use kmail again (since Thunderbird 
butchered the PGP and its integrated support if it is subpar).

But kmail again stops working after short while - all emails are in 
"Connection Established" state (in config - accounts - receiving).

Quick googling leads to threads from 5-7 years ago, again pointing at 
fault of Akondai.

Was this a mistake to use Akonadi (or add enough polish to work over 
this problems)?
Should someone start kmail3 that actually can be usable?
First of, the error reporting/debugging is not intuitive nor informative.