I disagree with your second assertion: if the streaming services go bad, the alternative isn't paying for all the music you've been paying for again; the alternative is pirating it all of it for free.

That's the beauty of the services: they have to compete with free and to do that they have to provide a superior enough experience to the user. If that ends, the music industry is the loser.

Your solution is explicitly illegal and not always possible. Not all music is so easy to find over time.