Exactly. Most businesses can get away with not having developers at all if they just glue together the right combination of SaaS products. But this doesn’t happen, implying there is something more about having your own homegrown developers that SaaS cannot replace.
The risk is not SaaS replacing internal developers. It's about increased productivity of developers reducing the number of developers needed to achieve something.
Again, you’re assuming product complexity won’t grow as a result of new AI tools.
3 decades ago you needed a big team to create the type of video games that one person can probably make on their own today in their spare time with modern tools.
But now modern tools have been used to make even more complicated games that require more massive teams than ever and huge amounts of money. One person has no hope of replicating that now, but maybe in the future with AI they can. And then the AAA games will be even more advanced.