They do guides because people need them, if the toys give you out the battle, nobody will watch their guides. And if you check the streams of Xeno and other hardcore players as him, their views jump from 1k to 15k when there is new content that people want to see cleared. When you have more and more tools to clear it day one before guide and you will not need to figure it out blind, people will not go to watch them, but just go and clear. And don't forget no matter if you like or not specific streamer, this is business model. Streamers don't put "good job" comments as food on the table. Videos with high view count may help better with the food.
I agree for ultimates, so far I can't find full group of 8 people crazy enough to clear them entirely blind. I personally clear content only in blind, so if there is no people for something, I just avoid it until I find. But I am looking forward to it, there are few people that started to feel the hype for it.
Something unrelated that I noticed. Stop the fake news. There is not a single streamer that was banned for using dps meter. Even Xeno, Zepla and Arthars agreed all banned streamers were using cheats after they saw more detailed info about what mods were used by banned streamers. SE do not ban for mass reports because they do this manually. For unaware souls, mass report ban works when it is bot enforcing the ban. The guy that became popular in Japan was banned once before for using cheating mods and it was not huge surprise for taking another one for it, it had nothing to do with him being massively reported because he is white in Japan as many tried to "fake news". My concern and all the points I explained down are related with possibility of SE to enforce their rules.
Right now the arrogance of people that use insane amount of mods is in "they can't know if you do" because Yoshi said they don't want to add anti cheat, but that was not solid statement as it will never happen, this entirely depends on the community. At the same time way before anti cheats were a thing devs were just adding "traps". I believe system like this is used against mods in FF because there are really not a lot of them, but pretty much it works by the devs dowloading targeted mod and look how it interacts with the game. They find interactions that can't be achieved in normal play and add code to check if those actions are performed, this can be done both on game files and only client side stuff and server side changes. And SE may start doing this at any point if they decide specific part of the communiy crossed the line too far, as in my opinion they already did.