I also find this painful and have switched to iceraven, a fork of Firefox Android that supports arbitrary addons, and use SingleFile to save webpages as html files.
Because not many people use it. I don't think many people have the desire to save a whole web page. For other unseen you can probably just get away with taking a screenshot, sending the tab / sharing the link, or using an archiving site to save it for later.
"Because not many people use it" was the excuse Google gave for killing RSS.
Google Reader ≠ RSS.
RSS is dead?
* check own RSS feeds *
Nope, still alive
I certainly don't use it since it's gone, I have to save pdf on desktop and then rsync it to the phone.
I used that all the time. Saving an entire webpage as just one single file with all images and resources embedded was a terrific way to archive pages and resources in research. Of course pdf was works great too but you lose the flow of a browser.