ok, but then your free time isn't +50% because you're spending that extra day on labour to now compensate for the lost savings.

Don't get me wrong, both myself and my wife are both working 4 day weeks after the birth of our son (culturally, that certainly helps the discussion), and that extra flexibility let's you choose the option that's best for you, but there is an opportunity costs trade off between them all...

Painting a garage door is very different work than staring at a computer screen and interacting with coworkers. Some people enjoy physical labor occasionally as a nice change of pace.

Yeah physical labour on my own property isn't work to me either.

Alternating your "main" job with other physical work, perhaps outside, is much more healthy both physically and mentally.