I think you would be right in a lot of cases but does that apply when you routinely sell out these extremely expensive shows like are being discussed here?
Taylor Swift probably has it better than most artists, considering she’s probably the most famous music artist on the planet right now, and even if you only make a small percentage off of ticket sales, a small percentage of an astronomical number is still a big number. I’d still be willing to bet the bulk of her net worth is in the rights to her music though.