Good video but I'm surprised he didn't talk about optional content. That imo is the best way to handle difficulty when it's a game that can support it.
From platformers to puzzlers, it's common to give players access to the ending way before they reach 100% completion. Struggling players will be happy to have reached it and will call it a day (like me in Hades) while better players can keep going for even harder challenges.
With multiple endings it can be even more interesting. Solving harder challenges can lead to even harder challenges and good/dedicated players can experience content that bad players didn't even know exists. This is common in puzzle games like FEZ, Tunic, and The Witness. As long as the easy ending is bad/obvious enough, dedicated players know to keep going.
