I know an editing experience is in the works for Experience Builder and I am excited to see what the team comes up with. However, I'd say I think there might be a really simple and elegant shortcut here for the team to consider.
While the Survey Widget could probably be used to create an editing experience, that's inefficient because you have create a separate survey item for each layer and then really get into the nitty gritty of carefully crafting schemas to make it work. It is possible nonetheless and with enough work, can be pulled off pretty well.
However, there's a simpler approach. JSAPI 4.x already has an Editor and FeatureForm widget. I'm speaking without any knowledge of the details but I would think that both of these widgets could probably be brought into Experience Builder with relatively minor amounts of work.
Take the example of the Map View template on a mobile device. It's a beautiful, professional looking map app that works pretty well as it stands today.
There's a glaring layout inefficiency here though that cannot be resolved currently. In order to view feature data, you're required to split the viewport between the map and a page. That kind of layout can be useful in many situations but in many others, it just takes away valuable screen real estate.
However, many of the Experience Builder widgets such as Basemap Gallery, Measure and LayerList expose their widgets through a panel that slides up from the bottom.
Well, if the Editor and FeatureForm widgets were brought into Experience Builder, since those are JSAPI 4.x map widgets I imagine they would also expose their elements through this panel, which would be great because then we would not need to use a survey or some other work around to deliver a simple and intuitive editing experience.
Further, if the LayerInfo widget could also be configured to surface in this panel, acting simply as a popup, then there would be no reason to split the screen just to view and edit attributes. The map could consume the entire screen in that case which would be a much more intuitive and pleasant experience.