I was talking to people I know about this topic and looking for obvious big success stories of vibecoding replacing enterprise tools like Atlassian I found they are very hard to find. At this stage I have no doubt that there are IT departments trying to displace SaaS products and re-engineer legacy systems, but it's probably too early to measure results.

And you're not likely to see any either, frankly, because you buy SaaS when you don't want to DIY.

It's easy to think of DIY software as "free" because you don't pay seat licenses, but DIY is expensive like a free yacht is expensive. It's a bottomless pit of money and time and upkeep.

Even if it's simple to implement, you still have to support it, update it, get people to use it, be on call if it tips over, teach people to use it, be forced to take it over when the person who wrote it leaves, etc, etc, etc

IT is a cost center and isn't staffed at the level of your revenue generator eng teams. You don't buy SaaS because you don't have other options, you buy SaaS to throw money at a vendor to take care of a problem for you, so your IT people can do the work you actually want them to do and not dick around rebuilding software that you already have.