It's a side effect of the switch to Qt for the UI tech, that's why it first appeared with 2017 with the new UI.
Each UI component needs to be updated (ported over to Qt), they clearly cared most about ART and Arnold, leaving out Scanline.
Even when using ART or Arnold, the General and the Render Elements tabs still have this issue.
Yeah, it's a huge mess, and to leave it like that for 3 years... no words... Making some noise on the Area or letting them know on their blog where they presented their roadmap may help to draw some attention. Then again, rest assured they know about it and you're not the only one to complain.
My guess is... 2 years. Let's see.