This is a duplicate of AGO Recycle Bin Please visit that idea to vote and comment.
It would be really helpful to be able to have deleted items from ArcGIS Online go into a 'recycle bin' that you had to empty - or some other similar feature that allows you to have some protection against accidental deletions. Businesses and other users keeps extremely critical data on the ArcGIS platform especially with field data being collected. If it gets accidentally deleted there is currently no way to have it recovered. There is currently no backup functionality on ArcGIS online other than manual download of individual layers - so if something does get accidentally deleted there is no way to get it back. I understand you can turn on delete protection - but that only goes so far - if something IS accidentally deleted you are out of luck. And for a business - out of luck could mean out of thousands of dollars and broken contracts / legal liability. ArcGIS Online adds all sorts of advantages to storing data in the cloud to be updated by field staff and shared on webmaps - but if that data exists only in the cloud (like daily updated field data) if it gets accidentally deleted you have zero recourse. Adding a recycle bin type of thing where deleted items are gathered in a folder and must be "deleted again" to confirm would be the minimum way to solve this problem. The best and most appropriate way for a top-tier mission critical enterprise service would be to go even further and add the ability for administrators to recover deleted files (for a limited period of time after deletion, maybe). I use many cloud services and recover deleted items is just a basic feature. Honestly, it's kind of crazy that ArcGIS online lacks these features in 2019.
I understand that the typical response to a request like this is "be careful and don't delete things" and/or "download all your edited data daily to prevent accidental data loss". But it's just like seatbelts and traffic lights: "be careful and don't crash into anything" or "be careful and look both ways at an intersection". That won't cut it in the real world. We have the technology to fix these things!