A 100% increase in software development velocity is a wild claim to assert at this stage. The industry as a whole is not seeing anything like that and the handful of people making claims to that end are executives with a vested interest in boosting the hype. LLMs probably increase prototype or ad-hoc script development by that amount, but that only accounts for a minuscule amount of actual work being done in the industry.

Also whatever LLM productivity gains are currently happening are being massively subsidized. Once companies switch out of lighting money on fire mode most of these products will get dramatically worse and more expensive. Maintaining a cutting edge LLM isn't a railroad that you build once and can run and manage for centuries at a fraction of the initial price, they require constant expensive investment.