And subsequently, the entry level trim which nobody buys got axed in 2021
Exactly: even if someone could produce such a cheap car, you wouldn't get a lot of people in the UK actually buying it -- regardless of whether it's electric.
Most people want crash safety and power seats and emergency braking and navigation systems, and everything else in modern cars. If they can afford it they are willing to pay for them. The few people who don't want those things are already driving some 1990s economy hatchback held together by duct tape and they like it that way. They aren't going to buy your new car either.
So to sell such a cheap car you would need to either do so in a market that values those features less or aren't willing or able to pay for them. Or make a car that people in the UK actually want.