JS is absolutely not required for any of it.
I think it's a little bit awkward to not use put, patch, delete... I wonder however if my server must follow the same technique, if not how to wire a delete endpoint to handle a form post and so on. I'll try to handle a form using only get and post sometime just to see how it works. Thank you!
I've always hated put/patch/delete because it tends to result in data centric UI's instead of workflow centric ones.
Anything you do on the client side via JavaScript can be bypassed by the end user and provides no guarantees about the input you receive.
When I learned HTML4 forms and CGI, javascript was solely the domain of input validation if it was available.
Okay I definitely feel old.
https://developer.mozilla.org/en-US/docs/Learn/HTML/Forms
https://web.archive.org/web/20110117085131/http://w3fools.co...
Even if they have fixed all these instances since then, that all those errors were ever produced is a bad sign, especially when there were better alternatives even then.