[KronisLV]

That is a valid premise indeed, but one that i cannot agree with for a plethora of reasons. There are articles that go into more detail about what this approach leads to: https://idlewords.com/talks/website_obesity.htm

There are also aspects which are probably entirely overlooked because of that approach, for example, consider:

  - https://whatdoesmysitecost.com/test/210813_AiDcEB_e62852d10cb795009ccd61f1dd2d8623#gniCost
  - https://whatdoesmysitecost.com/test/210813_AiDcPZ_dd4b52c10c37e4c7483ab391015a00cb#gniCost

Sometimes, there are also accessibility concerns (especially in the case of Flutter), all of which will work against letting your software be used by as many people as possible, in as many hardware and software configurations as possible.

If the target audience of your products and sites are wealthy and able bodied individuals in 1st world countries, then by all means go ahead. However, in certain other pursuits inclusivity is definitely an important goal as well and one that i personally value a bit higher than fancy looking sites with rich functionality.

That said, isn't 20 seconds a bit much? Sure, i get that it's just an example, but i think even heavier pages like GMail load in approximately half of that. I think that bundle splitting and some optimization are probably a good idea even in heavier pieces of software!