Support for high DPI monitors has been included in Fedora Workstation for some time now. If you use a monitor with a high enough DPI, Fedora Workstation automatically scales all the elements of the Desktop to a 2:1 ratio, and everything would display crisply and not too small. However, there are a couple of caveats with the current support. The scaling can currently only be either 1:1 or 2:1, there is no way to have fractional ratios. Additionally, the DPI scaling applies to all displays attached to your machine. So if you have a laptop with a high DPI and an external monitor with lower DPI, the scaling can get a little odd. Depending on your setup, one of the displays will render either super-small, or super-large.
Both of these limitations have technical reasons; such as how to deal with fractions of pixels when scaling by something other than 2. However, in a recent blogpost, developer Matthias Clasen talks about how the technical issues in the underlying system have been addressed. To introduce mixed-DPI settings, the upstream developers have per-monitor framebuffers, updated the monitor configuration API, and added support for mixed DPIs to the Display Panel. Work is also underway upstream to tackle the fractional scaling issue. For further techincal details, be sure to read the post by Matthias. All this awesome work by the upstream developers means that in a Fedora release in the not to distant future, high DPI support will be much much better.