It's literally basic web 2.0 junk from the early 2000s, the UI has barely changed since it launched.
It's possible to make a web 1.0 HTML email client but GMail is much much better. It's the difference between 1998 MapQuest and Google Maps.
No one in their right mind who does a lot of emailing would use it compared to the normal one besides for ideological reasons.
That's perfectly fine. If you can't see it, you can't see it. You need to know what to look for to see it, though. If you're oblivious to web development then every page is just a page.
> You receive like an email a minute?
Irrelevant. The range of operations that Gmail supports and falls within the lazy classification of CRUD operations goed way beyond sending and receiving emails. For example, see gmail's support for tagging, email classification, multiple types of inboxes, etc.
> It's literally basic web 2.0 junk from the early 2000s (...)
Tell me you're completely clueless about web development and WebApps in general without actually saying it. Just keep in mind that you also have the option of not commenting on things you're oblivious about.
Petty sniping is not welcome.
Of course, there are webs which are developed with the worst practices and bloated to oblivion. But even the best websites with the greatest UI/UX and perceived performance will have at least some complexity to it to give that experience to the end user. UX and simplicity done right is really a craft that mixes creativity, human psychology and technical skill.
A linear form with help messages is better than any gimmicky design one can think of.