Software wants to be installed in C:\Program Files so that other software can’t modify their installation without admin permissions. Of course to do that your installer needs to be run as administrator which makes the whole thing rather silly.

Software installed through the Windows Store seem immutable enough even though they live in the user's AppData.

At least the system prevented me from seeing or modifying the files the last time I tried. I did not try very hard, admittedly, but by contrast modifying something in C:\Program Files is just one UAC confirmation away.