My music style is far from trendy, but I can't remember the last time I listened (even more so bought something) from the major label. I'd say is much harder to become millionaire rock star now, but for indie bands, that play as a hobby, situation is very favorable as you can contact you audience directly and you don't need to frame yourself into "format" dictated by the labels.
It's an amazing time to be a hobby musician. You can record and produce your own music very cheaply and publish it to the world at the touch of a button. The problem is what happens next, which in most cases is nothing, unless you've got somebody spending money marketing your music or you're willing to work very very very hard to promote it yourself.
The difference between now and the 60s through early 90s was that labels were willing to put their weight behind more oddball artists like Bowie. He wouldn't have a snowball's chance in hell of achieving the same fame if he were starting now. We're in a weird time where mainstream music is the most timid and cynically commercial it's ever been but the fringes are exceptionally vital.
Bowie's first albums didn't catch on at all. It wasn't until he decided to change his presentation and style that he became successful. I recommend seeing "David Bowie & The Story of Ziggy Stardust" which talks about it. It wasn't until Hunky Dory in 1971 that he really got traction. He was dropped by his label (Mercury) after his third album. He signed with RCA for his 4th, Hunky Dory (Ziggy was his 5th). After that, he basically hit single digits for his peak chart position in the UK for in to the 90s for his studio albums.
So, you can look at it as Mercury took a chance, didn't succeed and dropped him. RCA tried again and succeeded. But, he changed his approach and style around this time in an attempt to market himself better. Then, EMI would reap the rewards again in the 80s for Let's Dance which hit number 1 in a half-dozen countries and close to it in a few others.
Even after he made it in the UK Bowie still couldn't crack the States. His US Ziggy tour was a mostly unsuccessful attempt to have him fake it until he made it. He had to nearly go disco to become a commercial success in the US. Bowie seems to have been the beneficiary of a degree of early patience from record labels that was fairly extraordinary even at the time.
