I believe this has to be adjusted through SharePoint by creating a custom permission group. In the custom permission level, you need to uncheck the box that says, "Delete Items" under List permissions. Then it should go away. Since you can't add custom CSS in the responsive forms, I don't think there is another way.
If a complicated workflow assigns tasks to multiple users and one 'idiot' deletes their task, I would have to get everyone else to abandon their already completed tasks and start again.
It makes perfect sense to have this kind of 'hide delete button' as an option, if our CSS is blocked. There are CSS settings in Responsive forms. But very limited so far. Adding ribbon options here would be helpful.
I have added this to the Uservoice page as a suggestion.
Any workaround to hide or disable the delete button ? I developed the entire form using Responsive form and now my customer wants to remove/disable the delete button from the ribbon.
Thanks in advance.
Use SharePoint permission.
Create a new custom Permission Levels without the right to delete item (for exemple create a copy of "Contribute" permission and unchekc the "Delete Items" right).
Change the permission of your list to use this new custom permission.
You user will not have the right to delete item, and so, the delete button will be disabled.