It could be true I guess, depends on the person and the work.
After years of fronting bands and having a lot of fun but not making a lot of money, I wanted to earn a living as a musician so I made it happen. I built and perfected a very marketable solo act, booked all the venues and events I wanted to play, played over a thousand gigs and it was pretty awesome for a while.
But eventually, after quite a few years it became just a job and the only reason I was still doing it was for the paycheck. I had some issues with my vocal chords for the first time in my life at one point and determined I'd rather preserve my voice for future opportunities that are more, let's just say, musically envigorating, than potentially destroy my voice for just to make my nut every week, and I mostly stopped with the solo work.
There were other reasons, I had quit drinking and didn't want to be in an environment where I was having free drinks pushed in my face 5 days a week. For all the great and fun gigs there's a lot of shitty low energy rooms too. That gets really old after a while. I absolutely abhorred having to constantly advertise myself and my own name on social media. I'm very low key and I don't care for that kind of attention but you have to promote as a "pro" act or whatever, its just part of the business. God do I not miss that shit.
At a point it stops being about music and it just becomes, I'm selling a product. The other thing is playing solo can be very liberating. To have full control over your entire songlist, read the room and call your setlist throughout the night on the fly, to arrange songs however you want in whatever key you want, these are things you don't really get to do in a band and there's a lot of freedom in not having to clear every decision through 5 other people. But it's also limited in not having other musicians to bounce energy off of. After long enough I just felt like a monkey clapping symbols together for people.
It's important to note that we change as we age, our interests and priorities. What you think is really cool at 30 isn't necessarily going to be the case at 45. I'm way more into growing my crops and produce today than I am into music and this wasn't even a part of my life 15 years ago. I have the opportunity now to grow enough food to sell it, but I'm weary of going down the same path and ruining another passion of mine. Sometimes its best to keep a hobby a hobby, even if it's somethnig you take very seriously.