There’s a department at my workplace where this is common practice too. My old department worked with clients in similar ways, and I was half expecting we’d also be required to do it, but luckily that never happened. Further proof that, at this (generally progressive, flexible-working) company, your actual work-life balance heavily depends who manages you.
Agree that part time staff was odd to include here. I have no idea if you are part time. I don’t keep track of other people’s schedules. I would find it helpful to know you aren’t available the rest of the day in case I need something sooner.

My project is entirely phone based and we don’t have voicemail, either for the project line or individual staff lines. We used to, but we found we spent so much time returning voicemails and getting people’s voicemails that it led to us missing calls and going in an infinite loop.
The use of humans is weirdly condescending to me, like people who say ‘doggo’ sincerely. It seems incredibly off at work.