For the vast majority of software out there, this quality gap simply doesn't matter. Not everything is big tech, needing internet scale. Most software built by developers at non-tech companies are simple line-of-business apps used by a handful to a few dozen or maybe a few hundred people to do a thing a bit better than the Excel spreadsheet that was used before.
And AI has essentially automated the development of this kind of software. Or rather, it has dramatically increased the ability of skilled developers to produce larger amounts of these kinds of systems.
Excel hardest hit.