I think there might be a few things to consider here:
1. Is it without any loss in productivity? Or are they so productive/skilled that they can still outpace most other devs even without the IDE's additional functionality?
2. Is there a loss in productivity, and they just don't realize it? Just because they can still do a good enough job without an IDE doesn't necessarily mean that they couldn't do a better job as experienced IDE users.
This is similar to the arguments people make against using Rust. "I can code C just fine and never have any issues, I don't need Rust"
It's also similar to this Copilot discussion. The people who say "I don't see any benefit from LLMs when coding", could it be that they just... don't have enough experience using LLMs? We've -just- had that come up in HN[0], where everybody in the comments was showing how they got the answer just fine out of their LLM of choice, while the OP was all about how AI couldn't possibly understand that bit of code.
But I guess you're right that we can't trust word of mouth and don't know for sure until/unless we have an agreed measure of productivity and can run with/without or before/after type experiments.
Give competent developers - i.e. people trained to solve optimization problems in their sleep - a metric to optimize for. Call it "productivity". See what happens.
This is a fact that needs more attention, and it's why I prefer to onboard people with setup documents they work through rather than a canned working development setup, even though the former takes "longer" to get people up and running. The long term benefits in forcing people to touch and familiarize themselves with as much as possible far outweigh any short-term time gain.
I can't think of a worse idea than giving copilot to a junior dev... I use chatgpt a lot, but I've got lots of experience. One has to understand how the big picture works very well to not find yourself led down the wrong path.
Most non-technical business stakeholders don't really understand what we do. You don't see shows about awesome devs doing awesome shit, like you do for lawyers, doctors, business people, etc. All they know about us is that we're nerds who work like two hours a day and can't be bothered to go into the office.
They do, however, understand ChatGPT and how it can be used to create whatever you want (see also: Eric Schmidt's missive to Stanford business undergrads that made the front page here some time back).
Given this, they are EXTREMELY incentivized to give/force upon ChatGPT to juniors. If they can give this to juniors and maintain feature velocity with an acceptable amount of quality degradation, then they can eventually move software development to lower-cost countries with weaker worker protections wholesale (and use good old fashioned protectionism to make sure that those countries don't try to steal our slice of the pie).
Quality issues can be fixed by expert consultants who know their shit, but that market won't be big enough for all of us.
You do, but it's even more ridiculous nonsense fantasy than a typical doctor or a lawyer show (e.g. all the hacker girl scenes like https://www.youtube.com/watch?v=hkDD03yeLnU, https://www.youtube.com/watch?v=u8qgehH3kEQ).