Yeah I was surprised not to see the opportunity cost angle in this article. For high income tech workers the opportunity cost can be huge

Depending on the job, you can also do it better yourself than what you can reasonably pay for.

I built a custom shelf for my closet. It'd have costed me an arm and a leg to have someone else do that, even with a tech worker's salary.

I also built a custom walk-in closet. It took me a day, saved me over 2k and I got a better quality closet out of it. (You find find built yourself a walk-in-closet kits that are easy to assemble, it really isn't that hard, just don't get the home depot level quality ones.)

It definitely depends on the job. Enjoyment is certainly a factor too.

Depends if you would be getting paid during the time spent doing these projects. People with flexible vacation time might even be getting paid while doing the work. But otherwise weekends and evenings are great times for smaller home projects.

There are other opportunity costs other than direct monetary income.

For example, to mow your lawn, you have to find a time to do it every couple of weeks when the weather cooperates, be at home at that time, store and maintain the equipment, have a pair of "grass shoes", clean up afterwards, etc.

This might be worth the effort if you don't have much disposable income. But if you have money to blow, hiring someone to mow your lawn can give you more time to do something else you'd rather do.