madmozg This is because Figma added a new color calibration system on the Figma Desktop app in 2023, which seems to be one of the only apps I can notice temporal dithering with my eyes even on usually totally stable dither-free setups.
Other Electron apps like Visual Studio Code and Discord still feel comfortable on my stable setups, so this is a Figma Desktop-specific issue. Here's why:
Before 2023, Figma Desktop used to use a "sRGB or Unmanaged" color mode choice for the entire app. After 2023, the app supports multiple color profiles per file and allows you to choose sRGB or Display P3 depending on which document is open. This means the desktop app now renders colors totally differently, as it needs to be able to support multiple color profiles at the same time.
To get around this, run Figma in a browser, where it won't have the same level of color management capabilities as the desktop app. Both Chrome and Firefox seem to improve things, since I use Firefox for Figma on most machines and Chrome on one. I also force color profile to sRGB in chrome://flags. Try Firefox if Chrome doesn't work.
Overall, the shimmering feeling is gone after switching to Figma in the browser, and the app now feels as good as it used to in 2022 and earlier. (I can also notice an immediate difference switching back and forth from the desktop app to the browser version)
BTW, you can still use the official Figma Font Installer browser plug-in to use custom fonts in the browser version, meaning that there aren't any significant capabilities you'll lack from not using the desktop app.