Banks are a good example. I don't think they are losing much money with their software experience. There are of course some under performers that are losing customers. But it's mostly to other banks that are delivering a good enough experience. Overall, they aren't losing any business here. If anything, they probably spend too much on their software teams. The results are mediocre and it's taking them too long.
Corporate websites (also mentioned in the article) is another thing that just doesn't matter that much. They are good enough mostly. It's fine.
Measuring frames per second is a thing for web developers that suffer from OCD. It's not a real world metric that matters at all.
Now a point that might be a bit painful to hear for the author. These slides are a bit ugly, unsophisticated, and bland. And it looks like a hand crafted thing and I assume that the author is very proud of the skill level and craft involved. I'm sure the FPS metrics are awesome. But if you are looking to wow your audience with arguments, it helps if you can back that up with a slide deck that re-enforces that argument. Browsers can do better than that 1997 unstyled power point look.
And that points maybe to a thing in our industry where the people complaining the loudest are doing the least to solve their issues. Open source is fine. If you don't like it, make it better. That's how it works. Being an innocent bystander is a choice, not a necessity. If you believe the web is so bloated, make it better. And if these slides are the best you can do on that front, then you'll probably struggle to convince a lot of people.