Blurry Fonts in MacOS Catalina for Non-Retina Displays

This might be a duplicate of this post, but is has already been closed for discussion, so I'm opening new thread.

My testing consisted of:

MacBook Pro (2019)

DELL P2317 (FullHD 1920x1080)

IIYAMA PL2792Q (UltraHD 2560x1440)

Original USB C to HDMI connector

HP USB C to DisplayPort docking station.

To illustrate what happens I made a screenshot (difference is seen only when viewing on Retina or 4K display):

Non-Retina display on the top and internal built-in display in the bottom. It is obvious that on non-retina display fonts are blurred. I tried all possible mixes of connectors and monitors - nothing helps. I tried console magic:

defaults write -g CGFontRenderingFontSmoothingDisabled -bool NO
defaults -currentHost write -globalDomain AppleFontSmoothing -int 3|2|1|0

Also does not help.

I tried forcing RGB mode using this guide https://www.chanhvuong.com/4403/fix-blurry-text-on-mac-using-external-non-apple-monitor/ - still same ugly fonts.

Even tried to connect MacBooks of my colleagues to my displays - same issue.

At last I opened support case in Apple with number 101002333156 - second day of explanations and proovings that this is exactly MacOS 10.15 issue - either bug or intended. Tens of reload, rolling back to defaults - nothing helps.

Now tried to run Windows and Linux on this MacBook and what do you think? Fonts became normal. I don't know what to add... shame on you, Apple - hundreds of people have already mentioned that this is wide problem and still no solution or even adequate reply or comment.

MacOS is famous for it's graphics - many designers and text editors choose it for clear look and stability, but what do we see now? If Apple thinks that such solutions will make people to buy their XDR displays which cost like a Boeing wing they are making mistake - users just will jump to another OS or even change their laptop.