You would be surprised.... a lot of flippers and even non-flippers betting on the ability to easily refi 5 years out.

Publicly reported data:

https://www.cnbc.com/2022/04/27/adjustable-rate-mortgage-dem...

I know this article is about the US, but in the UK, 30 year fixes are very rare nowadays. Most people are on 2 to 5 year fixes which revert to adjustable or trackers. The norm here is to refinance to a new fix every few years.

If rates were to go up to 8%+, a lot of homeowners here would be unable to meet their repayments. The basis of the stress testing we've been doing since 2014 was only whether people could afford their mortgage if rates rose by 3%.

Pretty much the rest of the world except america

Not the last 5 years - the last ~8 months.