If I were to guess and remember my time working at a 'hot desking' company, it's because on login, the user's profile will be copied from a central server onto the local system.
I found out this is a thing when Chrome and Firefox started to put their files in the user's home directory by default. If that has to traverse a network - and who knows where all that data is coming from or how fast the internet connection is - that can take a long time.
There's a few ways to set up profiles in Windows, and most of them are terrible. If you have the joy of stepping into a network with roaming profiles enabled, you will discover it takes years to untangle.
The idea that you can log into any PC and your local desktop and documents all appear seems really nice, but the implementation weeds are nasty: I tell people to store things they want to access on multiple computers on a network share, and we replicate basically nothing between client PCs.
Outlook also likes to download a large chunk of a user's mail archive locally each time you open it on a PC, but you can configure it a bit, and Outlook generally "works fine" while downloading. I suspect it gets hairier at DOD scale though.
Onedrive has helped a lot. But only if you can make your users actually use Onedrive. More likely they invent some asinine workflow and save their documents in the most illogical places that will never get synced and you never manage to catch. Also causes problems when trying to recover data from corrupted user profiles.
Even better - Java devs who use the default settings for Maven will have their entire local repo copied over the network.
At my company people would remotely log in on Sunday evenings to avoid the hou long wait while a few hundred gigs get copied across the network. Why not chnage the location of the local repo, you ask? Of course our machines are locked down and we have no access to the local drive...
That's the difference between %APPDATA% (AppData/Roaming) and %LOCALAPPDATA% (AppData/Local). Caches should go into local appdata, or %TEMP% if you're feeling spicy.
I remember "fixing" the university's computers by preventing the browser cache from being downloaded. at every Windows startup. That was maybe 15 years ago?
I found out this is a thing when Chrome and Firefox started to put their files in the user's home directory by default. If that has to traverse a network - and who knows where all that data is coming from or how fast the internet connection is - that can take a long time.