'Fractional scaling is practically necessary if you’re running a HiDPI display, and you want your desktop to scale uniformly to match your display. It’s always been an issue on Linux, but the latest version of the GNOME desktop has implemented a true fractional scaling feature to keep your desktop looking good.

Even though GNOME 3.26 does have fractional scaling support, it wasn’t mature enough to make the release. As a result, it’s still a testing feature that you need to enable yourself.'

-- source: https://www.maketecheasier.com/enable-fractional-scaling-gnome/

Cheers, Peter