https://pi-hole.net/ is a project to consider for home and small business networks that you're looking to protect via DNS without sending all your requests to a third party.
What’s nice about pi-hole is that you get one request to sites like google.com until the record expires in the cache. If you use 8.8.8.8 as your dns you might end up requesting the same domain name a bunch of times depending on how your client caches and the caching is at 8.8.8.8. So dns will see lots of requests to the same domain.
Although this doesn’t count on-client caching, it still seems to back up your guess and my original comment.