Most of the time I write code to defend against future me, because I know that in a few days I'll have forgotten half of the code along with all the optimization hacks in it.
You want "Save to my calendar" but we still don't have full support for date inputs. Chrome has supported the main features since 2012, Firefox joined only in 2017, and we're still waiting on Safari to make a move.
Well, I wanted "Save to my calendar" when our self-built date inputs still opened new windows with html tables as calendars to pick a date, but I get your point and I lumped this under "forms suck". I still shudder when thinking about implementing multi-file uploads in php.
That's true. But with TS I have to declare types, import typings, maintain a build process to run the TS compiler, and so on. Moreover, static typing comes with added tediousness, and I personally feel that it's not worth the freight.