Is there a way to organize YouTube channel subscriptions in the Roku YouTube App by topic/folder? There are ways to do this on a PC browser (e.g., the Chrome extension PocketTube), but I don't see any similar functionality on Roku. This is really needed if you have dozens or more subscriptions.
Send feedback for YouTube on TV
choose "suggest a feature", then "other" and explain your request
I agree with you, but I don't know how I'd implement it.
I have Youtube Premium, hopefully that feedback page is available regardless of that fact.
The link you provided appears to be for Youtube TV, not Youtube's Roku app. Are you aware if Youtube offers a mechanism to provide feedback and request enhancements for their Roku app?
Look again.