Musicians are expected to practice an ungodly amount of hours (no, the amazing piano player you just listened to isn’t born that way).
Designers are frequently expected to have a portfolio, a lot of which they did in their spare time. When asked how to get good, they’re told to “draw, draw and draw some more”.
Doctors sure as hell don’t have time to keep up with the state of the industry while dealing with patients at the ER and they have to be on pagers.
The person who delivers my pizza is paid per hour and often has to take random shifts at any hours.
My plumber comes in in the middle of the night over an emergency.
Let’s face it, unless you’re doing repetitive clerical work, jobs are not 9–5. Even if you’re not expected to learn and do side projects, there’s till pagers.
So the only argument is “are you paid for it. Software engineers in the US often start at 80–100k or more. Their total comp can rival or even beat lawyers and other high end professions. The pager duty and the side projects to learn are baked into that compensation. You didn’t really think software engineering was so hard it deserved that much money, did you?
I worked for companies that only expected 9–5. Any time we had to use a new technology the company paid for professional trainers during work hours. Those companies exist. We were also paid 1/5th of what I’m currently paid.