I think AI is just allowing everyone to speed-run the innovator's dilemma. Anyone can create a small version of anything, while big orgs will struggle to move quickly as before.
The interesting bit is going to be whether we see AI being used in maturing those small systems into big complex ones that account for the edge cases, meet all the requirements, scale as needed, etc. That's hard for humans to do, and particularly while still moving. I've not see any of this from AI yet outside of either a) very directed small changes to large complex systems, or b) plugins/extensions/etc along a well define set of rails.
"I could make that in a weekend"
"The first 80% of a project takes 80% of the time, the remaining 20% takes the other 80% of the time"
That is a good point and true to some extent. But IME with AI, both the initial speedup and the eventual slowdown are accelerated vs. a human.
I've been thinking that one reason is that while AI coding generates code far faster (on a greenfield project I estimate about 50x), it also generates tech-debt at a hyperastonishing rate.
It used to be that tech debt started to catch up with teams in a few years, but with AI coded software it's only a few months into it that tech debt is so massive that it is slowing progress down.
I also find that I can keep the tech debt in check by using the bot only as a junior engineer, where I specify precisely the architecture and the design down to object and function definitions and I only let the bot write individual functions at a time.
That is much slower, but also much more sustainable. I'd estimate my productivity gains are "only" 2x to 3x (instead of ~50x) but tech debt accumulates no faster than a purely human-coded project.
This is based on various projects only about one year into it, so time will tell how it evolves longer term.
So, my answer would be no. Tech debt shows up even if every single change made the right decisions and this type of holistic view of projects is something AIs absolutely suck at. They can't keep all that context in their heads so they are forever stuck in the local maxima. That has been my experience at least. Maybe it'll get better... any day now!