I’m not sure that statement is ever true for any value of <x>, as any task in iTunes is non trivial given what a painful experience using iTunes is.
That said, I can confirm the rest of the point, having made custom ringtones and pushed them to my iPhone on a few (painful) occasions.
Step 1: create an aac-encoded file with the .m4r extension to its name
Step 2: connect phone to Mac and drag and drop .m4r file on to iPhone on desktop
Step 3: there is no step 3
For those who want to do this without needing a Mac or PC there are apps that will do the job as well.
I know macOS Store subscription management is, hilariously enough, still just in Music app. (I wanted to cancel MS Office subscription - for Mac! not for iPhone! - and I needed to do that in Music app.)
It never occurred to me that iTunes should be required for anything, seeing as I haven’t used that piece of software for 10+ years. I suspect that applies to most iPhone owners these days as well.
As such this is trivial in the same way finding the news about the interstellar highway in “Hitchhikers guide to the galaxy” is trivial. That is, not at all.
And I have such traumatic memories about iTunes with it randomly wiping my iPhone several times a month 10 years back, there’s no fucking way I’m ever going to use that software again.
This needs to be solvable on the iPhone itself.