If you mean List view from the youtube Subscribe page I think what that means is that you are either on an old youtube layout and the new layout has not been rolled out to you yet or they re-introduced the List view and you are on a newer layout than me... Normally I try to keep legacy code for old youtube layouts but its really hard to test the code changes locally once Youtube decided to update my layout. In my next update I will try to tackle that problem and make the subscription filter independent from youtube layout changes.

Response to Lee1121: I was looking into it the day you wrote your comment, to get an idea how feasible it is. It looks more complicated then I initially thought, so I would say at least a month. (This is a non-profit side project so it depends how much free time I have)

User story: Change current filter from manipulating the HTML page to manipulating the underlying JSON data. (In hopes youtube changes their data structures less often then their layout)

Update 24/09/2023: I made a first prototype to do a proof of concept for the new change. Working out some details and corner cases in the next few weekends. Just wanted to give a quick update and say that the change seems doable and its actually a fun challenge.

Update 27/09/2023: Filter on initial data when youtube page loads the first time is done and filter on subsequent data loading when user scrolls works as well now. Next up some code cleanup and after that I will do some testing period locally for a week or two and see how it behaves and if I missed something.

Update 30/09/2023: Refactored the code a bit and fixed some issues. Theoretically everything works fine. I'm just not happy that when a user goes from the youtube homepage to the subscribe page I need to force to reload the page because otherwise I can't manipulate the initial data from youtube. Some further digging is needed to figure out how to make that a better experience.

Update 1/10/2023: User experience is as good as I can make it. I still have to reload the whole page when the user closes my filter add-onn popup but I can't think of a single thing I can do about that. Reload between context swapping like homepage -> subscription is not necessary anymore though so that's cool. Still testing a bit but the update should be there in the worst case on the 06/10/2023.
Code changes can be reviewed on: https://github.com/KallocainSynthemesc/Subscription-Filter.

Github: I did a lot of Java development but barely had Javascript experience when I started this add-on and so I did not feel like putting the code out there visible for everyone to read. I'm still not extremely happy with the code, but at the same time I think it might be interesting for everyone to see whats going on behind the curtain. I'm probably going to add it on the main page next update.

Update is online, please tell me if it works correctly