I don’t. This isn’t how Facebook works. Paid opt outs drain the highest-earning advertisees from the pool. That removes Facebook’s ability to charge dubious ad rates.
Do you mean "user" by "advertisee"? If you do, it is like Stallman saying "used" for SAAS users.
At its very beginning, WhatsApp was a paid app so that wouldn't surprise me
It would surprise me. The first thing Facebook did when it bought WhatsApp was to rollback the price on iOS and to halt the Android pricing rollout. They don't want you to pay for it, it singles the remaining (ad-served) population out as being less willing to spend money. Not a good message to your advertisers.
I'd rather pay than see ads, but either way I got a better alternative waiting for a network effect (Signal).
I already paid for this app. Why should I pay again?