Because I don’t want my work to be able to literally watch and record every keystroke and mouse-click I make. Much less listen or watch me at home by activating the mic or camera. There’s no way I’m using that compromised device at home regularly.
I have a work laptop I only rarely use for just one very specific thing that I can only do on that laptop. I also have my personal laptop where I do everything including my work and if I want to sidebrowse stuff then I open up a different browser—all of which are privacy-hardened.
I just recently got a new laptop so now I have one that is even more locked down, secure, Linux-based, and I only use it for personal stuff.