The claim you are responding to is that Resolve is used "at some step" in the vast majority of films, not that it is used specifically for cutting the vast majority of films. For example, Resolve might be used on a DIT cart for on-set color work, or it could be used for color grading in post—even if the film is actually cut on e.g. Avid or Final Cut.

Resolve's editing features are newer and less established, but I personally really like them.

For anyone interested in trying Resolve, I strongly suggest taking a look at Blackmagic Design's own oft-overlooked training material, which is put together by professional trainers and does a great job of working in useful concepts, workflow tips, and keyboard shortcuts at just the right times. The free video tutorials are a good place to start, and the free PDF books offer more of a deep dive. Project files to follow along are also included.

https://www.blackmagicdesign.com/products/davinciresolve/tra...

(I've posted about Resolve once or twice before; for the record, I do not work for BMD, I just enthusiastically like them.)