So for me, as I stumble and bumble my way through learning French (mostly through DuoLingo, hey), I'm often thinking about this issue.
Now-- on the surface of things, Modern English is almost exclusively comprised of German & French, and almost every word in these sentences are specific examples of such in terms of direct etymology. Which is a big part of why I've typically regarded French & German as my sibling languages. It's a nice, bright thought, anyway!
Let's take the modern English word "fight"-- WP claims:
From Middle English fighten, from Old English feohtan (“to fight, combat, strive”), from Proto-West Germanic *fehtan, from Proto-Germanic *fehtaną (“to comb, tease, shear, struggle with”), from Proto-Indo-European *peḱ- (“to comb, shear”).
My point is that there's so many ways to run with that over time... in any language whatsoever! Indeed, IIRC there was a "fisten" variation which meant an entirely different thing in earlier German.
But, "shear?" Yes, yes back in my schoolyard days, I wanted to shear my opponent like a little lost lamb, but... I don't think that's right.
So here's my point, assuming you've lasted this far. Modern German in fact split from modern English maybe around ~~800AD? And Modern French, around... perhaps slightly earlier than the Norman Conquest (1066), meaning that even though Modern English is absolutely PACKED full of French & German pronyms, we can't just assume they mean the same thing, anymore, as with the examples above.
It sort of breaks my heart, but it's just reality, non?
Absolutely, I totally agree. It's Impossible to artificially keep a language alive, and forcing people to learn/use a language is wrong.
It's just sad, that's all. It's like seeing a local shop close and getting replaced by a shopping mall, and then that mall closes and is replaced by internet shopping. Reality moves forward, but it's not necessarily a bad thing.