Mixture is spot on for the corporate environment, where most PCs will be running a standard setup and all the important stuff is on a central server. If it glitches and the fix isn't easy, wipe and reinstall. When I worked, the Systems folks had all the popular configurations on the main server ready for this (frequent) eventuality.
I disagree for a home PC, where there may be a wide range of software that's been installed over a period of time, and where the originals have been lost (or were downloaded and the URL isn't carefully recorded). Installation codes may not be to hand; personal settings may not be easy to recall...
The last time my PC had an attack of the vapours, it took me a long day to reinstall all the stuff I wanted - I didn't bother with some because life's too short to download dozens of rarely-used large programmes on a slow ADSL connection. (I now keep all downloads on an external drive, which has saved my bacon a few times when software has disappeared from the Internet). Being a tidy bunny, I have all the unlock codes etc stored in an Excel sheet (copies of which are in several places including my iPad).
If it hiccups, wipe-and-reinstall would be the last resort: it took me weeks last time before all the software was reconfigured to the settings I like. Excel, Word and the like are easy because they use settings files in known locations and which can be backed up. Some stuff probably does, but they don't tell you where those are, and reinstall doesn't pick them up.
Re-install also allows some infuriating software to put stuff where THEY want it, like buried umpteen levels down in the "Users" directory on drive C, when I want it in the top-level directory on drive I (or wherever). Even when they are told to put it on drive I, some of them also create their own "C:\Users\..." folder and put some key stuff in there. Apple and Ancestry are particularly bad at that - my SSD went from 51% full to 80% full before I found that iTunes was ignoring instructions and stuffing a full backup of iPhone and iPad in there every time I plugged them in. I had to be very forceful to persuade it that I'd really meant it when I said "H:\itunesbackups\
If your PC has a basic Windows (or whatever) installation, with a couple of added software items and not much unusual stuff, then reinstalling every year or so might clear things out a bit and gain a tiny performance improvement. If you've got a load of stuff stretching back a few years, think carefully!