I might've misspoken, I didn't mean to imply the UK didn't contribute significantly to these fields, it's that they didn't manage to establish themselves as major players.

I assure you I've heard these sentiments from real Brits.

While I'm not going to question the contributions of UK people and companies to these fields, but with the exception of RR, none of these companies are actually still in the hands of Britons, DeepMind is Google, ARM has been brought out by SoftBank (and Imagination that used to do the GPUs for the iPhone has been kind of sidelined).

The UK is not percieved as a mover and shaker in the rocketry industry like the USA is with SpaceX and the like, and not even to the extent other players like Russia/China are.

Sota AI is made today by US and Chinese firms, while the UK might have an extensively built out green infrastructure, it's made out of foreign-made equipment, no UK company makes EVs like the way Tesla or VW does etc.