The spelling checker problem in browsers

Recently I put myself the last beta firefox for poppy.
Somehow she happened to be Russian.
It turns out that Firefox can check Russian spelling too.
It is very cool.
Here I suggest that Google Chrome can.
Then I have this question:
Manufacturers of brewers do not think that a person can write in English and Russian from one browser?

Source: https://habr.com/ru/post/55407/