"Locking in" a rate for multiple decades is mostly (only?) an American thing:
* https://www.tandfonline.com/doi/full/10.1080/15214842.2020.1...
* https://www.investopedia.com/why-your-30-year-mortgage-exist...
* https://www.cnbc.com/2024/05/07/why-the-30-year-fixed-rate-m...
* https://www.deeded.ca/blog/why-canada-doesnt-have-30-year-fi...
While a ≥20 year amortization period is common, the mortgage term is generally shorter (2-5, 10 years) is most other places.