To be fair, they are not the only ones that use this "story" as a ploy to get more control over users (and hence gather more saleable personal information).
Phrases like "make the web faster" are disingenuous and should not pass any intelligent user's BS filter.
The very reason the web is slow is because of these companies which need to serve ads and other crud to survive. That means more DNS lookups, more TCP connections, more HTTP requests, more Javascript, longer URL's, more unwanted IMG's (e.g., beacons), more tags, etc., etc. The list is so long I cannot even hope to capture it all. That end result is simple: staring at a screen waiting for the computer to respond. Not to mention frequent leakage of personal information.
As a user of netcat and text-only browsers that retrieve pages in milliseconds, I am astounded at how long users today are willing to wait for their content (i.e., "page loads"). I also run my own web servers at home to serve content to my family's mobile devices. I am well-aware of what (i.e., who) slows down "the Web".
The user does not start from the assumption that she needs to (down)load "resources" (as in Uniform Resource Locator) from a number of advertisers for every page she views. Those are the assumptions that the web company starts with. Those are the constraints they must work within. Not true for users.
I do not need Google DNS. I run my own locally, primed with all the domains I routinely visit. No remote DNS cache is going to be faster than my loopback.
Nor do I need HTTP/2. I just use HTTP/1.1 pipelining to retrieve 100's of pages of content, usually 100 pages at a time. HTTP/2 is something the web companies may need to accomplish their goals of serving ads and collecting personal information. But it is not something users need.
To drive adoption they must convince users that users need these "improvements". So the web companies purport to offer "solutions" to the problem they themselves created: a slow, bloated www.