Would love to be in a situation like this. How do you find a job that lets you do nothing? I’d be happy to work on personal projects, learning new things, working a second job, etc
You aren't allowed to do these things on your first job.
What you are suggesting is almost equivalent to squatting in an apartment for free and then renting it out to someone else to earn money.
Also, many people work on fairly locked down computers with nothing much to do aside for (filtered) internet and random "corporate" apps. I'd be quite surprised to learn that in these kinds of situations, where people are required to be physically present to do nothing, they would be allowed to bring in their own computers and openly do private stuff.
This is the part I don't understand. If your job's expectations are so lax, why not potentially double your income?