2. Impossible to secure - Yes security is a huge issue with the web. But a large part of that is older designs and many have been mitigated (as an example, the wiki section the author links to show why JSON is insecure has 2insecurities. Security issues in parser implementations which are not written in web technologies anyways and the fact that before 2009 and the widespread availability of JSON.parse and JSON.stringify people used eval to parse JSON).
I’ll be honest that I do think the web needs to be improved/changes/replaced. I don’t think this article makes the point well and possibly focuses on the wrong things. But my biggest concern is with the idea that improvements need to be achieved by replacing the web instead of the kind of incremental improvement we are already seeing.
I would be interested in Part 2 to see if the replacement the author has in mind is really worth it. It would need to at least be an order of magnitude better to sacrifice the compatibility advantages the web has, but it may still be worthwhile to think of what a platform written today from scratch would look like to focus the kind of improvements we would like to see on the web.