Supervisor vs systemd

What is the benefits of using the default supervisor vs configuring bench for systemd via:

bench setup systemd

if you prefer systemd instead of supervisor then use it.

everywhere in community and docs supervisor is used.

My question was why frappe would add an extra dependency to use supervisor when it could simply use built-in systemd ?
Is there anything supervisor does that is not provided by systemd? Or is it frappe wanted to be agnostic of systemd?

supervisor is the default process manager since beginning. systemd was added later. Everywhere you’ll find supervisor is used because it was there since beginning.

2020 onwards I’m not using supervisor or systemd. I’m using containerized setup for development as well as production.