2. the house price will not go down 30%, not mentioned the rent cost set a limit for how low the house price can be (comparing rent a house to own a similar house, it dones’t make sense to compare renting a 1 br apartment to owning a 3-4 br house with private yard)

Of course it will go down but not 30%, perhaps more like 40-50%.

Cost of ownership is not just the mortgage payment! What about property taxes, HOA, maintainence/repairs, insurance. All those are absent in rents. If you figure in the whole amount of owning it is now over double that of renting an equivalent place.