[zabzonk]

>I meant the work laptop you are given through working as a SWE.

Everywhere i've worked, i was not "given" a computer anymore than I was given a desk, a chair or a network connection. Perhaps "provided" would be better.

> And are you allowed to use your own personal computer (laptop)?

Never have been, and never have wanted to be.

>why are people OK with it

It's industry SOP, and people pay you to work that way.

> I cannot imagine being productive without my OS, WM, IDE, configurations and whatnot.

You need to improve your imaginative powers, and your technical knowledge.