I'm speaking from the perspective of a site, like Backblaze, where web app and the site fulfill two separate functions. There are lots of cool metrics that marketing wants; any code they put into www.backblaze.com is pretty low cost, and usually done by a separate team than product.
The product site itself (usually app.example.com, but Backblaze seems to use secure.backblaze.com) actually contains customer data in the browser context, is under much higher base resource loads from its core functionality, and is used repeatedly in workflows where poor performance is painful to the user.
No one gives a shit if your pricing page takes 500ms to load instead of 100ms, or if a dozen social media companies who already know where you work learn what kinds of professional products you're looking for.
They do care if a file listing takes longer, a recipe opens slower, if word frequencies in confidential data are leaked to the world.
In most paid products, the non-paid part of a site has radically different performance and security requirements from the paid part, and forcing one to be built to the requirements of the other (in either direction) is wasteful, or dangerous, or both.
The product site itself (usually app.example.com, but Backblaze seems to use secure.backblaze.com) actually contains customer data in the browser context, is under much higher base resource loads from its core functionality, and is used repeatedly in workflows where poor performance is painful to the user.
No one gives a shit if your pricing page takes 500ms to load instead of 100ms, or if a dozen social media companies who already know where you work learn what kinds of professional products you're looking for.
They do care if a file listing takes longer, a recipe opens slower, if word frequencies in confidential data are leaked to the world.
In most paid products, the non-paid part of a site has radically different performance and security requirements from the paid part, and forcing one to be built to the requirements of the other (in either direction) is wasteful, or dangerous, or both.