I think he makes a few good points, but they're also an overcorrection.

He says "because that early mana could have been spent on something that’s generating value over time". There's almost nothing that gains more value over time than having additional mana sources and card draw sources.

He also says that fragile ramping isn't that strong because the payoff is that you're the first to do the most threatening thing, and that means people will have answers for your thing. This is definitely a good point, but it is also solved by not overextending. Just because you have enough mana to do something doesn't mean you do it. The problem is solved just as easily by not overextending. The solution is not to just disable yourself from extending when the time is right to do so, because then when you actually need the mana you won't have it.

Slow and steady is sometimes safer, but fast and explosive is also a calculated risk that can pay off by just outright winning.

When I want to play slow and steady, my decks typically rely on engines. These engines are often in the form of card draw... and ramp. I'll have more instant speed interaction and protection in these decks, such as a [[queen marchessa]] deck. I can cast a rock on turn 2 to get her out on turn 3, and she's never the 'big threat that people will hold up answers for because I cast her early'. Instead I use her to accrue card advantage and I keep ramping.