Certainly not impossible. I don't find LaTeX hard to install, at least on a modern Linux distribution such as Ubuntu (and if memory serves, it wasn't hard on macOS either).
I agree that setting up a basic template from scratch can be tedious and I wish this was better, but the common approach for newbies is to copy a template from somewhere, and for more advanced users, they probably have some base template with personal tweaks that they keep reusing (I know I do, not only because I hate Computer Modern).
There are still a whole number of issues with LaTeX (such as incompatible packages, the inconsistency in font handling between pdflatex and xelatex, beamer is generally IMHO a mess, etc.) but what GP wrote - that old documents will continue to compile and give the same results - is true.