In the USA it’s pretty standard. The 30 year fixed rate mortgage is probably the most popular by far. And then you refinance it over time as rates fall.
Adjustable rate mortgages exist too but got a lot of people in trouble in 2008. I think a lot of them are only allowed to adjust by a certain percentage regardless of interest rates each year they’re eligible to.
It also keeps the minimum payment lowish - I went for a 30-year fixed, refinanced it once when rates went crazy low, and paid roughly double what I needed to (apart from months when I couldn’t). It paid off in ~13 years. I could have got a 15-year fixed on slightly lower rates, but the flexibility was worth the rate delta for me.
Adjustable rate mortgages exist too but got a lot of people in trouble in 2008. I think a lot of them are only allowed to adjust by a certain percentage regardless of interest rates each year they’re eligible to.