As others have said this is interesting but use of Ultimate Guitar is flawed as the tabs/scores are so bad on that site, very often not even being close to the real chords.

On top of being simplified tons and tons of songs get rewritten with a Capo so people can just play G-C-D shapes, if your analysis doesn't look for "Capo" and then transpose all the chords then you end up overrepresenting the key of G and it's chords. Then very often 7th chords, Sus chords, etc.. all get transcribed down to major chords & minor chords due to the beginner focus. Interestingly he doesn't include 6th chords as their own thing.

To be fair there are tons of songs that do actually use those chords, so they may still end up coming out as the most popular.

I have a grandfathered in lifetime membership to UG that I only had to pay once for. It was cheap so worth it, but I really find the site kind of icky as they are mostly monetizing crowd sourced low quality work and it's very often wrong. And they nerfed their iPad app recently which is really annoying.

The fact that the data showed only 6% of Metal songs having power chords should've told him to throw the data out the window. UG has terrible tabs/charts.

It's really not that bad. It's a mix. There are also many versions for most songs and often comments with corrections.

Learning songs by ear is probably a useful skill that people don't develop because of all the other sources of information... but probably helps more people play which is good.

They have quite a few versions usually but the most accurate version is usually the one with far and away the most positive reviews/upvotes.

The power tabs and guitar pro tabs are a big step up over the text based stuff on ug. You can play it in midi and see they are usually perfect.