query regarding git merge

Hi, I am confused with git merge working.

Suppose I have these 3 files in master branch- a.txt b.txt d.txt

I create a branch, add c.txt to it and commit. So its final contents are- a.txt b.txt c.txt d.txt

Then, I checkout master branch, delete a.txt, add e.txt and commit. So final contents are- b.txt d.txt e.txt

Now when I merge branch in master, its result is- b.txt c.txt d.txt e.txt

Now suppose in branch, a.txt was needed for its working. And in master branch's latest commit a.txt was removed because maybe it wasn't needed or it was introducing bugs. Now, git merge removes that a.txt So now branch functionality wouldn't work. Isn't that wrong??