There's a ridiculous amount of bugs in the mobile editor, and the WYSIWYG buttons are extremely limited compared to the desktop editor. The other day I pasted a definition from Google, and I was not able to change my font back, this limiting my font to the one from what I pasted. There's a great number of things that you can do in desktop that can't be done on mobile, which make it hard to write posts the way I'd like. Erasing text is especially a problem.
I'd post an example of the bugs that occur while erasing text in a spoiler here, but there's no option for spoilers on mobile.
I'd just like to know why the mobile editor is so borked, on behalf of myself and many others who struggle to get the mobile editor to do what we tell it to do.