I know this, because I've built two side income businesses, sat back and collected money only to find competitors had taken me over. They weren't big by any means but the $3,000 a month I made off one and the $1,000 a month off another was quite nice. I could've quit my job and traveled, but instead I paid down my mortgage and banked/invested the rest. This left me with a lot of money (for me). I eventually sold both businesses when I saw the writing on the wall with various competitors and industry changes.
I did end up traveling for a while though. I did that with a remote job. Sure I had to work during the day, but that left plenty of time to explore whatever city I was in at night and do bigger adventures on the weekend.
TLDR; 5-10 hour work week doesn't last.