Enterprise websites tend to have very complicated content generation systems with little care about performance (including html/css/js size). What's hypocritical is that Google penalizes in SERP sites which have poor performance score yet Google's own sites are far from exemplary.

Enterprise websites have often enough this issue.

they might have a composer layer which loads certain components (transparent to you) with and without authentication and mixing different backend sources.

Then they might have templating engines and frameworks.

Sometimes they just don't care but lets be honest: a few new lines are a few bytes.

But the most critical pages go through optimizers for traffic

Perhaps they used:

https://en.wikipedia.org/wiki/Whitespace_(programming_langua...

It's the watermarking of the AI they used :)