As others have pointed out, the Zoom part isn't the big problem here. The delivery is.
Just for starters, within under a minute he's made the whole thing about him. Comments like, "Last time I cried," and, "I hope I'll be stronger this time," are grossly inappropriate. Nobody gives a shit how he feels, nor should they. This isn't hard for him, it's hard for the people he's firing. He shows a complete lack of respect for his now former employees by making it all about him. He should have made it about them. He should have showed them some compassion and respect.
Then there's the framing, the room, and his body language. He's miles away, barely looking at the camera, and constantly referring to notes printed out on paper. Not to mention he looks casual to the point of shabbiness, both in his dress and his demeanour, and there's distracting clutter around him. This is not hard to get right: sit directly in front of your laptop, and close enough to show head and shoulders only; look directly into the camera; have your notes on the screen and aligned with the camera so you don't have to keep looking away to refer to them; above all, STOP TALKING ABOUT YOURSELF.
I could go on but the short version is that the way he handled the situation - a situation which for many of those losing their jobs would probably put them in dire financial straits - was extremely unprofessional and disrespectful.