Do you know how little money advertisers pay per ad? I think last I heard it's between 0.5 and 3 cents. Could be even lower. That's probably not enough, so they sell your anonymized data. That's not enough, so they offer a membership without ads so the ratio can allow them to get closer to break even. What's left?
The people getting the benefits of membership without paying for it. Third party apps letting you use premium features for free? Gone. Didn't push the needle far enough. Most of their userbase using adblocker? New target acquired.
They're very clearly trying to get their revenue and expenses to hit 1:1 because no company that's doing well is going to crack down on their users. Netflix was flourishing so they let you share accounts. Then, the bill came and they said fuck that. Their revenue and profits went up what, 60%? They just had to endure the people throwing tantrums.
No, they're learning that if 5% of the people using adblockers instead get Premium, they lose less money, even if it means doing what Netflix did and riding out the storm while people bitch and moan about how their free shit isn't free anymore. Should they help offset it by making Premium more worthwhile with features even third party apps could do? Absolutely. Do I hate having to defend a company that could be doing so much more to benefit their users but are making pretty common sense business practices? Absolutely.