But what's the end result? bubble pop or money die?

If they print and cause inflation it discounts the debt and people who have borrowed to the teeth get a cheap asset. If they try to stop inflation they wreck everyone who has borrowed.

We were conservative and bought an old smaller house to minimise debt. We plan to put on an extension, we spoke to a builder in 2020 at the start of covid who said it would be about 50k, but by the time we got plans drawn and a quote it's over 200k now.