GitHub repositories are open for the taking, GPT-XXX is cloneable (mostly, anyway) and VS Code is extensible.
They definitely have a good head-start, but I really don't think there's anything here that won't be generally available within 2 years.
I can think of no one but a handful of companies being able to compete there. And they won't be ok with extending a Microsoft IDE, nor breaking GitHub TOS.
When you start competing on R&D costs the game changes.
There's always the chance that training costs will significantly decrease. But even at an order of magnitude less (ie. tens of Ks) it's still beyond reach for open projects and indie devs