this is a fair assumption, ref this topic.
using the default block lists only feels like driving a sports car round the block in a 20Mph zone and convince yourself it's a powerfull car.
The default block lists do NOT take regional domains into account, one must add at least some regional lists.
edit
A long time ago, I wrote a topic about testing the value of new lists. I still use this on pihole v4, it works, the result is useful to the decision whether or not to add the new list.
So whenever I add a lists, I verify if is appropriate adding it (low new entries value -> don't add)...
/edit