If they rise the price or start showing ads you can stop paying for Premium, same as with any service that stops being useful to you.

Not sure why you need to mention the "renter" thing, this is literally a service you're paying for and that you can stop paying the minute it stops being useful to you. There's no vendor lock-in, just stop paying for Premium when if it ever becomes shit.

The OP is not saying Premium will always be good, they're saying why they find it useful to pay for Premium now.