I Want You - Marvin Gaye. The whole album. You'll know why.

Like I said, you'd better have been off asking why rock bands aren't growing that big anymore. But your question was if that type of music is still commercially viable, which it clearly is. Pop music being dominated by other types of artists doesn't change that.

It literally takes you two seconds to Google and get a way more complete response than I can ever give you. But if you insist me doing the work for you, here are some bands that I've seen at sold out shows at quite large venues the past few years:

Rammstein, Sabaton, Amon Amarth, Parkway Drive, Nightwish, Trivium, Mastodon, Gojira, Arch Enemy, Behemoth, Powerwolf, and more.

Doubt you'll care much since you already went into this with defined answer.

You can literally look up the Wikipedia article with the stupid amount of record labels that have specialized in rock and metal music and pick any band that has released an album with them in the past 15 years.

Also you constantly narrowing down your definition of commercial success doesn't help your point.

If by "viable" you only count bands that reached Metallica levels, then you already answered your own question and this thread was completely unnecessary.

You won't have to do much research to find dozens of rock and metal bands in the last 15 years with record label contracts. If it wasn't "viable", they wouldn't exist. Hell, you know that contracts could also be cancelled if bands formed before that stopped being viable? But if you're already going into this topic closed-minded you're just wasting your time.

That's your own extremely narrow definition of what's "commercially viable" if you exclude all bands that didn't exist 10 years ago. Clearly it's still commercially viable for big rock bands to go on tour and continue making music, otherwise it wouldn't happen. Perhaps a better question would be why there haven't been any bands that were founded 10-15 years ago that grew as big as the ones you mentioned in that amount of time? Probably more of a topic for a scientific paper than Reddit if you ask me.

Last time I checked there are still hundreds of metal and rock concerts/festivals selling out every year, so no.