This is the wrong way to think about things. You cannot usefully compare the value of time spent on work vs on hobby.
If I'm doing a project like installing the washing machine myself over the weekend, I value my time at exactly $0/hour. Let's look at the opportunity cost. What are the alternatives? On a weekend I could read a book, go out for a walk, play some games, etc; all those alternatives cause my income to increase by $0/hour. There is no difference in income amongst all these activities; there is only a difference in satisfaction.
You might say, what if you do this washing machine installation during regular work hours? Again the value of your time is zero, because in tech you are not an hourly employee: you get paid a fixed salary. Taking one hour off from work doesn't decrease your salary. Working overtime for one hour also doesn't increase your salary.
Therefore when I'm doing hobby projects I value my time at $0/hour. I think more about the kind of non-monetary satisfaction instead.