I live in the US, and I use a masher like the one you have pictured. My grown kids also mash potatoes that way.
I occasionally use a ricer, which makes nice smooth potatoes, but the ricer is a bit of a pain to clean.
When I was first married, I used an electric mixer, because that is the way I was taught to make mashed potatoes at home. But it is easy to overbeat potatoes that way, and they can end up tasting gluey if you're not careful.
We love mashed pototoes, and any way you get them to the table is fine with me!