Getting a meaningful market share of browser usage is very hard.
First, because most statistics are based on self reported user agent metrics from the top websites. But my parents don't go to Reddit, PornHub, YouTube or LinkedIn, etc.
Second, culturally speaking, I don't think we have accurate reporting of non-western websites. I bet most of China, India and Russia websites don't care about reporting their metrics publicly.
And last, internet usage distribution is very skewed. I myself probably generate 1000x more internet traffic as my parents, so I probably count as 1000x more market share than them. Yet, in terms of "users", I would count the same as they do.
To my parents, double clicking on "Internet Explorer" means "opening the internet".