Sadly, I think this is the result of big content companies seeing the success of the subscription model over the advertising model -- if I can get Joe Public to pay me US$5-10 a month for my stuff, I can lock them in. Converting from advertising to subscription is trivial, and there is money to be made there.

Sadly, no one can create good content just for the sake of the creation -- you cannot live in modern society on your creations or reputation alone. You have to monetize them somehow, and big corporations can be a great source of that money. The alternative is to pay the creators directly, but there are only so many Patreon and other individual subscriptions I can manage at US$5+/month, on top of other bills.

For the record, I've never used Stitcher nor SiriusXM, so I've no dog in this fight.