To be fair, there are also cases especially for older bands where their fanbase who were teens and young adults during their prime are now 40-50 year olds with families and are better off financially than they were back then.
They can’t. Gen X was the last generation that got wealthier with age and it’s gotten progressively worse for every subsequent generation.
They can it’s called getting a better job. There are tons of jobs out there making 100k a year in fields from computers to plumbing.