Completely wrong.
If builders aren't currently building like you say so all the time because it's unprofitable.
How would they build at all if every home cost £50k and prices never rose at all?
To encourage development and building of more houses the prices need to go up.
What your suggesting is a paradox where you don't want house prices to increase yet you want more development. Unfortunately inflation requires prices to go up and to make building them worthwhile.
But I imagine that your solution is developers should be building houses at a loss because they own too much land. Yeah I'm sure that will be implemented tomorrow.
So if prices don't rise. Nothing gets built and then even those that can afford to buy cannot buy new homes.
So it doesn't just benefit investors at all. They actually help homes be built for buyers who will live there.
That's just nonsense. If prices were stable for long enough they could just price in a margin as any normal business would and get on with it.
I suspect at some level speculating on the future value of a house once built is an unwelcome distraction.. like large scale FOMO, they have to do something otherwise they cease to be a developer so choosing when rather than just getting on with it at a manageable and plannable pace could even end up making them less margin as they're at the whims of labour and material prices more unpredictably.
Also this isn't a closed loop, the higher prices go the more wages go up the more general inflation is etc.. as I said, wooden dollars.