According to reports, Google Chrome is way ahead, followed by Safari and IE/Edge.
No real surprise there being as how ALL Android tablets and smartphones default to Chrome. Likewise, iPads ands iPhones default to Safari. It was no different in the old days before the proliferation of portable devices, where all Windows machines defaulted to IE.
It means nothing other than showing the shift from desk-based computing to being on the move. Computers users have always settled for defaults because they didn’t/don’t know how to get anything else. Personally, I use Firefox on my Smartphone. It just works better than Chrome for me.