I'm tempted to take the opposite stance to the author. The web as a platform is wildly successful, and it's interesting to think about why.
Surely the "loose" standards encouraged neat hacks that at some point were encoded as best practices and then standardized. Maybe that would tempt us to want to "cut the cruft" but a) people probably thought that many times previously and b) backwards compatibility is probably more valuable than one would think.
To say that web as platform is wildly successful would be an understatement. It's so successful that probably like 95% people doing webdev don't even care about these discussions or have opinions about it.
I think that scale of "silent" users compared to proactive devs would be the most surprising number. Like for anyone who is "Rethinking DOM from first principles" there is probably like 10000s of randos editing ecommerce html templates, exporting results into tables and dataviz or making small uis for some internal system.
Surely the "loose" standards encouraged neat hacks that at some point were encoded as best practices and then standardized. Maybe that would tempt us to want to "cut the cruft" but a) people probably thought that many times previously and b) backwards compatibility is probably more valuable than one would think.