Does that mean people shouldn’t try to stop it?

No, I think we should try anyway, but it will be extremely difficult to do and a lot more effort should be put in educating people about what price they pay for "free" product handing over their and others' data into the hands of a single entity.

How would you go about "circumventing" pi-hole? I do not allow DNS requests going towards Google's DNS servers by firewall. The only option would be to use a DoH but it is also blocked on standard ports. The only option is to use a non-Google associated IP with a non-standard port which is not worth it at the scale of Google.

As roughly zero people who would click an ad use a pihole, I'd guess roughly zero engineers are working on the problem.