The dreaded "process" to get a single tool registered, working and allowed, is the reason a company is slow, dysfunctional and usually failing at a task.
The security tax and speeding tickets on everything are a luxury destroying much value.
The problem with controlled environments is that even when done sensibly by people with good intentions they do slow things down and a lot of orgs will decide the trade off isn’t worth that.
I’ve worked for companies that did have much more controlled environments but given everything is made of a thousand packages these days and those packages have CVE’s and you do need to patch doing it after the fact is a recipe for paralysis.
The friction they should have probably had here is: did this employee need access to 3,800 internal repos?
I'm with the poster above in believing restricting what you can install makes a lot of things more difficult, but if you're going to take the risk you should be limiting the blast radius.