What started OS's expanding was the graphical user interface and ever
since then the more graphical abilities that were added increased the
overall size of the OS. Sure we could still be using DOS / Forth etc
and command line to do everything but that kept the use of computers
in the hands of those that could understand how to use them. The GUI
released the world of computing to the great unwashed and so heralded
the world of computers we see now. Without that, computers would still
be largely an elitist occupation with prices of systems still making
them out of reach for most folks. It's also debatable whether 'the
internet' as we have now would ever have evolved.

I agree that sometimes the pursuit of graphical nirvana has led to
code bloat on a massive scale and a slackness in coding has been
allowed to develop as restrictions of RAM / CPU horsepower were
lifted, leading to code that is larger that it could optimally be
written. There's a saying that any fool can make things complicated
and it takes a wise man to make them simple - a quick look at remote
controls for TV / Audio etc will bear that one out !!

Personally, I give thanks for the GUI / multi-tasking / drag and drop
world we live in