I think the reasoning behind this is that ideally you're at the location where you can confirm what you see, instead of maybe referring to older media or from memory.
That being said, I agree with you and would like to see more ways to access the tool!
https://MapComplete.org is made by someone from Belgium with the aim of making a website that's at least as good as a native app could be. It's both a data viewer and editor but generally that sounds like it's what you're looking for!
I have yet to get into it myself (I already have established workflows in StreetComplete and other editors) but from the demo that the author gave on CCC ~1.5 years ago it seemed perfectly usable back then already
You can edit OSM from its main site [0], although there's a much steeper learning curve when using the site (as you have far more freedom and it's not super easy to figure out the standard way to tag some situations).
Adding to that: StreetComplete specifically creates only quests for information which must be checked in the terrain like opening hours, surfaces, traffic light sounds. Anything surveyable from maps and other sources should be edited using the web editors. OpenStreetMap iD is probably the easiest to learn.
That being said, I agree with you and would like to see more ways to access the tool!