It’s your App. If you think your target Audience may need this feature, you should implement it.
You just need to make sure (test) that your variable Font and Size Settings fit within your Window/ListBoxes at Display Time. You should also test if everything looks fine on Scalings between 100% and 200% (maybe even higher?).
Modern versions of Windows and macOS support display scaling (HiDPI). Windows allows fractional scaling (100%, 125%, 150%, 175%, 200%…etc) while macOS supports whole scaling (100%, 200%, 300%…etc).
Also, with the question, I wanted to know how people feel about the size change inside the window (a bit like what is possible in the Finder with text and icons). In some folders, view by list, I increased the text size from 12 to 16 (the max in the Finder) and this is good.