The topics aren't perfect either, unfortunately. For example, Sublime Text, as we know it, was first released in 2008 while the topic trends data you linked shows it being the leader in 2004.
Would be interesting to know which percentage of vim searches are for vim keybindings in other editors. (i know several people who use vim keybindings, but don't know anywone who uses vim itself)
A little off topic: but when I was in uni our instructors insisted that we use vim for all of our development during the freshman year CS courses. Did everyone actually use it? Of course not, but a significant amount of class time was spent teaching keybindings, macros, etc.
I really built a habit of vanilla vim usage, and to this day I have yet to find a "modern" text editor that really supports everything that vim has to offer i.e. "vim mode" being more than binding the arrow keys to hjkl and providing modes.
I've found a lot support most of the standard modes / commands but not vim scripts (and partial ex mode quite often) . Which is often fine as extended functionality often comes through the host editor/ides native capabilities. The advantage being they can leverage things that just don't exist in Vim.
https://trends.google.com/trends/explore?date=all&geo=US&q=%...
(and if you keep it to search terms but swap "visual studio code" for "vscode" you see a simialar rise)