Follow along with the video below to see how to install our site as a web app on your home screen.
Note: this_feature_currently_requires_accessing_site_using_safari
If your sitespeed is slow or server response time is low then crawl rate limit drops and Googlebot crawl only a few of your pages. If your site is responding quickly then crawling rate may increase. You can setcrawl rate limit in search console.
Google who?
Googlebot is only fetching your HTML source (probably) PDF and other compiled files may be a resource problem.
Google Images is another indexing robot and story ...
Bandwidth is pretty cheap these days.