Glenn can come off as an asshole and this video absolutely had a clickbait title, but if you actually watch it, you'll see the point of this video is that basically "speakers are a huge component of high gain tone, and your amp doesn't make as much of a difference as you might think it does" which is absolutely true. And I say this as a guy who just bought a Wizard.
His videos are usually marketed towards people who like metal and are fairly new to guitar in general. You know, people who usually think the amp is everything, and that whatever speaker cab you happen to pull out of the dumpster should do just fine because they're "only speakers, who cares?" so overall it's a good lesson to teach those people.
The amps in Glenn's video sound similar and the amps in other peoples' videos sound different because they have knobs you can turn to adjust them. Ever taken a 5150 and cranked the Presence and Depth to minimize negative feedback? Since the Dual Recto has no negative feedback, you can get them to sound pretty similar if you try. And if both amps are boosted using the same boost, then you can get them to sound almost the same. Yes you can dial them to sound wildly different as well, and Glenn obviously didn't do that here to illustrate a point, which you can argue is or isn't deceptive, but in the end he was still using both amps and didn't lie about anything, and he did a decent job showing how drastic a speaker change can be.