I think B2 (small) B SaaS is also in trouble pretty much now. Enterprise is a different thing though, the barriers to entry are not just building and maintaining the software.
They wouldn't create a Xero replacement (although ironically I did vibecode a business order/finance tracking app for my own side hustle, fuck paying $30/mo when I just need the basics), they would vibecode any of the litany of small industry specific software packages they use.