So the reality is that the growth of the web far outpaced any sort of design principles that could have been implemented by any committee.
TCP/IP development happened quietly for the most part in the 1960s-70s. There wasn't a lot of pressure, and they had a decent amount of time to get the protocols right. There wasn't an economic demand for Arpanet.
And it wasn't until about 1993/1994 that the web exploded in use and popularity. That was only 4 years after TBL created HTML. That's when you saw the explosion of JS/Java Applets/CSS/Browser Plugins/etc.
In some sense, the same thing is happening in the python world. While python has been around for a while, there were maybe 800 python devs at Pycon 2010. In Pycon 2018 there were 3000ish(?).
I do agree with you that the Python 3 update wasn't done well, I think it is because they didn't predict the language's explosion during the 2010's.