Anyway I'm thinking this may have to do with something in my Windows 10. I've also noticed, since reverting back to default 100% desktop size, that the icons on the desktop are spaced FAR too much (see image). Again, no easy way to adjust that--thanks Microbrains.
These things are adjustable by editing registry settings.
If you do a google search you should be able to find the relevant registry entries that effect dpi, desktop icon size and spacing etc.
I believe there are also tools that can reset all Windows dpi and/or icon registry settings to the original values without you needing to open regedit.
But be very careful if this is new to you, you can make things worse or create very serious problems if you make mistakes in the registry.
I got the registry fixed for the icons. I also have fixed the MB text using a few other types of font sizing options. First, I'm not increasing the size of everything in the "scaling" option. if others are having any problems with their high DPI monitors:
1. Leave scaling at 100%, default.
2. In the programs you use, use their own internal font size options, like the one in MB or Firefox.
3. Problem: Windows title bars, menus, right click menu, and dialogue boxes will remain small.
4. Fix: Use the font only size option in Settings>Ease of Access>Display> [make text bigger]
Now everything scales perfectly because you haven't changed scaling, and you get a larger font in "Windows Only Programs." MB font size is not affected, for instance.
Limitation: Window's dialogue boxes, other than menus, will still display with small text. For instance, if you open the "System Information" app, although the menus and title bar will have inherited your increased font size, the dialogue box itself, that which contains the system information, will remain at the Microbrain's preferred unbelievably idiotic font size choice of. . .wait for it. . .9pt font.