We spent the last 20 years building a whole set of specialised little tools on the web to do specialised little tasks for businesses.
Now an LLM can do most of that, easier, and effectively for free. The first pass on a new problem is not googling to see if there's a SaaS for that, it's prompting an LLM to see if it can do it, or if it can build a tool that can do it.
Case in point: in my job we have to data-enter invoices. I have dealt with or in this industry for 30-ish years. I worked on various projects trying to get computers to read invoices, to various degrees of success. It's a hard problem; there's no standard format, or layout. Every company does its invoices differently. Some are Excel files, some are PDFs, some are Word docs, etc.
This entire problem vanished this year. You get an LLM to read the invoice. It does this more accurately than humans do. Job done.
There are entire SaaS businesses that read invoices that are now obsolete and have no moat.