I've done the same thing for a long time

The only extra thing is I set up autohotkey macros

For example typing $today or $yesterday will insert the date with a dividing line underneath to separate days into clear blocks

I've tried a lot of different note apps and what I eventually realized is that when it comes to work, I generally don't actually care about old notes 98% of the time.

I only really care about the last week or two and when everything is in one file its optimized for viewing that, like a working memory.

The text file ends up gigantic but its still small data for a computer even after many years of adding to a single file and searching is still fast.