That is also true. If you make it to the top of the mountain the rewards are huge. if you get half way up and then slide back down, it can result in years of hard work for absolutely nothing, and this is often down to nothing more than bad luck, or a bad manager, and no reflection on level of talent.
I knew a keyboards player in the 70,s who was superb. Would give Rick Wakeman something to worry about. His band made three albums, while the manager paid the band £20 a week. He left the band and had to sign on, as he was penniless and had a wife and three kids to support.
On the other hand, my kids went to school with Steve Harleys kids, and although he isn't a squillionare, the royalties from Come up and see me, along with is other hits, will keep him comfortable for the rest of his days.
This high risk scenario, along with the drugs is probably why my parents strongly discouraged me from trying for a career in rock music and steered me towards the steady 9 to 5 type of job.
I still deeply regret taking any notice of them. I could hardly have ended up worse off than I am now.