I have noticed this while working in a startup, how efficiency gains impacted work in the last 3 months with better coding models coming in. If you have someone senior that is effective at using these tools and can own the outputs and be capable of correcting things that are sloppy, you are immensely more valuable than 2-3 more developers in the same area of work. It's actually faster to empower fewer people than try to have 3 fast guys where there would be coordination overhead, which would become a bottleneck and bring down a lot of the efficiency gains. A good full stack engineer who can work with these tools at speed with caution is more valuable similarly as it requires less coordination. 3 junior devs shipping 90% good code and 10% slop would make the senior who is reviewing everything the bottleneck.
This sounds like a good idea for execution of small ideas but most innovative things are actually very fragile in the early stage. Its almost the opposite of failing fast for those type of projects that truly makes them successful, for example the ASML EUVL would have failed instantly given how "impractical" it was according to every major expert at the time. I think it is more useful to think of a balance between exploration and this type of fail-fast aproach.