Scaling is when you change the size of fonts, apps, etc. In Win10 if you chose anything above 100% everything becomes blurry. There's also a problem when you use multiple monitors with different resolutions. You move a window from one screen to the next and it doesn't scale properly. It's a known issue for some years, and I'd wish they solved it in Win11.
Ah yes! scaling of the UI has been fixed for me since Windows 11. I use a laptop with a 4k display, and an external display with a 2k resolution. That was really a mess with windows 10, since windows 11 I’m very happy with the scaling and external display support. Even the Win+P menu to change how the external display is being used is not as buggy as it was with Windows 10.
I only have issue with Telegram’s client, and that’s due to their use of Qt, which doesn’t support native UI scaling without relaunching the app.
But I would guess that may vary depending on your setup.