I believe it sort of has had for some decades - it's called LyX:
LaTeX code is not edited directly by LyX, though: you need to import and export it.
LaTeX code is not edited directly by LyX, though: you need to import and export it.
Sadly it never took off. These days I would choose Jypter notebooks or markdown files with embedded LaTeX math, which also gives you instant previews.
LyX uses .lyx files but is able to import and output .tex files - and the fact that you remember it as "just LaTeX" means the integration is good enough.
From their Features Poll[0] page:
"By a general consensus of the developers, using LaTeX as a native format of LyX is no option. Query the lyx-devel archieves for details."