In countries (B) and (C) this is very rare. Mortgages tend to be for at least 20 years and some are to even 40 years. Fixed rates are available for long periods and people rarely would change bank and mortgage.
In country (A) investors use interest only mortgages to buy a place an put it to rent. They can profitably pay more money than someone who would buy to live in, making the market quite "hot". In countries (B) and (C) the markets require investors to re-pay including interest, which makes getting a loan to rent less profitable and thus the market is less "hot".
Regarding your question about whether there should be a ban on "interest only" mortgages to favor live-in owners, it's a complicated issue that requires careful consideration. On one hand, interest-only mortgages can drive up property prices and make it difficult for first-time homebuyers to enter the market. On the other hand, they can provide a viable investment opportunity for property investors and contribute to the growth of the rental market. Ultimately, it's important to strike a balance between the needs of homeowners and investors while ensuring that the mortgage market remains stable and sustainable.