How exactly is it hashed? There aren’t that many possible phone numbers, so it might be viable to just try every valid number until you find one that matches

Blaming Spotify for this is like blaming the company that made your TV for showing you ads that are part of the broadcast. Unless Spotify makes the specific podcast you’re listening to, they’re just playing you the content someone else made, including the ads they included in that content.

I wouldn’t wait that long in the hope that Google release another Pixel tablet and that it then fixes the issues you have with the current one. IMO there’s too much risk that either they don’t release it, or they don’t release it at the time you’re expecting, or it doesn’t change things you care about, or they change the price/features.

I’d say buy the best (/least worst) thing you can actually get now.

Changing DNS isn’t the same thing as a VPN. Your traffic isn’t “tunneled” over DNS, it just changes which server your devices use to look up IP addresses. Your ISP can still see quite a lot, particularly if you’re using plain DNS rather than DNS over HTTPS or DNS over TLS.