More not subscribed people watching than subscribed probably means your videos are getting recommended to more people who dont already watch your videos which is a good thing
Personally, I found the final green star house in 3D World's World Crown harder than Champion's Road. I beat Champion's road with at least 3 of the characters but I don't remember if I beat the mystery house even once.
Darker side took me 2 weeks as a 10 year old and I cheesed the end half with glydon. Something mentioned in this video is you can cheese the fork part with glydon. You can actually cheese the whole end part with him (it is just harder) you can fly all the way to the bowser portal.
I'm not sure if crc was found before this video came out. But even if it was, checkpoints are disabled in Balloon World so you wouldn't be able to do it
Note: The all bowser story moons (except the Mecha) is possible to skip with CRC glitch, same for Cascade madame broodal with the Island Moons, but this is the Maximum for 1P
90% of the time, when a content creator promises a link in the description, the link is not there. Good on you for being one of the few who follows through
playing as toad on the wii u for mario 3d world is the hardest way to play this level in my opinion. tiny jump, slower than switch and no op dive or hover and without powerups i would say its the hardest level of them all