Not to copy, but to see which spot is still free.

Ads are largely public: the ad libraries of Meta and Google show you what is running. An ad that has been live for months is almost certainly delivering something — useful information without having to test it yourself.
If everyone is fighting over the same five search terms, that is rarely where you need to be. The question is which topics nobody covers properly even though people search for them. That is where you can rank within months rather than years.
Doing what the market leader does with a tenth of the budget produces a weak copy. The question is not how to catch up with them, but on which ground you don't have to meet them at all.
A question or project on this topic?