It's true that you can make an immersive-sim without the "Deus Ex" title, but over the course of four games they've built a sort of cohesive universe and storyline and many people - myself included - would really like to revisit that universe. DXHR and DXMD weren't the same as the original, but I didn't get the feeling that they were trying to reproduce it. I think they wanted to do a sort something in the same
style but in a way that appealed to a broader group of people, so it was necessarily simplified (and hamstrung further by being the first game the studio made, the Eidos/Squenix turmoil and finally the rush to deliver).
HBomberguy's video hammered on a few points to deliberately make it seem more stupid than it was, and he knows it because he pulls back and calls the game "fine". I have a fairly unique perspective on this because by pure chance I'd played through all the Deus Ex games in the months before the HBG video dropped so I had an extremely fresh perspective on it. I'd also played through the original Deus Ex as a kid so I got to experience it when it was new and shiny. The video is very careful about emphasising DXHR's weak points while downplaying or ignoring many of the original's issues (or flat-out lying about them). The latter two entries in the series were troubled for sure, but they were more than "fine".
Edit: Actually I just remembered I wrote up a list of issues with the review because my friends were talking it and I wanted to share them in a way that didn't blast a wall of text in the group chat. So just in case you're curious what specifically I meant you can check it out here (content warning: I am a bit sweary) https://gist.github.com/smcl/666a0156b13d7a681e0378b836b36e4...
Edit 2: Oops I am a liar actually, I didn't play Invisible War :-O