I had a really bad meeting one day that became the straw that broke the camel's back. When I went back to my desk, I saw an interesting job posting. I immediately fired up the company's copy of Word to draft up a resume, and used the company computer to send the email from my personal account. Less than a month later, I was working for the new company. It was done intentionally. I almost sent the resume via company email, but I really wanted to ensure I could access any response.

> It would never occur to me to use an employer's hardware for such a purpose

That's a very uncommon mindset and worldview.

For 99% of people, the default would be "I'm going to join this Zoom meeting from the laptop I use all day long to join Zoom meetings, and I'm going to code using the laptop I use all day long to code".

Lots of people have their work tools setup on their work computer, but not on their personal computer. Their personal laptop might be relatively underpowered and struggle to run all the required software efficiently during an interview. The issue becomes even more significant as more of the tools used require an account - you don't want your interview performance to suffer because you're using an unfamiliar tool or service, so you just use the ones you're used to using every day.

If you work from the office, and they have tight security, they might frown upon bringing personal devices to connect to the internal network.

Also, some people might not have dev environments set up on their personal devices. Heck, a lot of people only use the internet through their smartphone, when they're not at work.