The only alternative is AGC's Dragontrail, which is popular for lower-mid range phones like the Oneplus 11r. They've never directly competed with each other in the marketing space, but both have been making significant improvements on drop resistance over the years. I'd assume competition is fierce for contracts at the edges of their territories. For high end phones, glass technology is a highly marketable feature because people care about potential damages to their device.
There hasn't been a direct promotion, demonstration, or comparison between the two for drop tests though. Corning doesn't have a reason to bring up their competitor, so I'm wondering why Dragontrail isn't aggressive in marketing their products as a cheaper equivalent. Their brand equity is small.
Are they so inferior? Well, then it could explain why corning has such a presence in the high end market. If they are similar, then it's suspicious indeed.
Therefore, EU should also take a look (not investigate) at AGC/Dragontrail glass and it's competitiveness to understand the industry as a whole. Maybe that's what kickstarted the whole thing.