That's an odd comment to make, you just inadvertently proved their point. Most large web products are serious (?), have 'proper architecture' and hundreds of frontend developers working on them. Google products, Spotify, AirBnB, JIRA/Atlassian, Booking.com, Trello, GitHub.. you name it. You may also notice TypeScript in the first paragraph of the report, which is a type checker and has been enjoying massive adoption.