That's exactly what's happening. Many claim they are more productive with AI, but individual rise in productivity just doesn't translate to projects being completed any sooner.
And by "projects", I mean corporate ones with big teams involved. Hobby projects actually do get finished much faster.
In the corporate world, writing code was always a small chunk anyway. Iirc something like 30% of employee time. Getting 50% faster there still only gains back 10% of your time.
To further complicate matters, you had to spend on AI software and potentially additional on legal/risk/security/compliance to enable that.
The smaller the company, the bigger that % of coding is of total time (all the way down to hobby where the majority of time is spent coding)