> I am confident a human and about 5 minutes with chrome debugger would yield better results
It really depends which human. I've worked with very few engineers who were good at this sort of optimisation work. A depressingly large percentage of people who make websites for a living don't really understand how http requests are really processed, or how to read and use the chrome profiler and benchmarking tools.
Claude isn't as good at optimisation work as someone who really knows what they're doing and goes deep on a problem. But I'm optimistic that it will help plug a capability gap in teams which don't have this sort of expertise on hand.
(That said, the chance that people actually learn this stuff is going to also go down if people get used to outsourcing this work to claude.)