Sites that are traditionally called walled gardens (facebook, AOL, compuserve...) often combine four features; (a) all the content is hosted under the walled garden's domain; (b) the walled garden designs key parts of the navigation and layout, understandably acting in their own interests; (c) the walled garden has content policies and declines to host certain content; and (d) users must have accounts and be logged in to see the content.
AMP does (a) and (b); I don't know about (c); and doesn't do (d).
Still, I can see why people see echos of walled gardens in AMP.
The feature that defines a walled garden is the wall. AMP doesn't have that wall: it is perfectly usable by any other search engine/spider to replicate the experience. The website itself can link to the AMP version if that makes sense for users. Mobile browsers, or web servers, could check for and redirect to the AMP version.
There's a slightly-higher wall for advertisers, I believe. But Google is rightfully afraid of antitrust issues and seems eager to get advertisers besides themselves signed up. But it is a wall in that it requires whitelisting, as far as I remember.
There's a lot to criticise about AMP, but I don't think the
"walled garden" metaphor fits.
Here's the wall: could any competitor to Google itself ever be on AMP? (E.g., a competitor to search, Gmail, YouTube, or adsense/adwords.)
Or would it have to be something on the open web? And if only AMP pages get ranked well on Google in the future, how much harder would it be for such competitors to ever get noticed in the first place?
> And if only AMP pages get ranked well on Google in the future
Currently, the only thing on Google results explicitly limited to AMP is the mobile news carousel. Presumably AMP pages also do well on the "loads fast" evaluation that affects normal rankings, but in theory it should be possible to do equally well without AMP. If this is changed, or turns out to not hold up in practice, then there is cause for concern, but I have not seen evidence of either.
News sites, of course, don't generally compete with Google's core services - unless you count Blogger, but in that case all news sites do). The one thing I can think of is that they might embed videos hosted on competitors to YouTube. When it comes to that, AMP is a mixed bag. Unlike on the open web, video players that use custom controls/iframes (like YouTube) need to be explicitly approved, since there's not much alternative without granting a blanket license to put arbitrary sites in iframes, which would (mostly) defeat the purpose. So Google acts as a gatekeeper. On the other hand, the spec [1] already lists like a dozen random video hosts you've never heard of; that's not evidence that Google wouldn't try to block a more serious competitor to YouTube, should one ever spring up, but there's certainly no evidence that they would.
Unless I'm mistaken, they did experiment with various attempts to highlight their own video offerings beyond what popularity dictated before finally giving in and buying YouTube.
And we all remember the kinds of crap Google did to try to foist Plus on users who had no interest in it. At one point 1/4 of the annual bonus of everyone at the company was tied to it.
With AMP, I get a different search ranking if I use Google’s AMP version, or if I self-host the AMP scripts (to prevent users being tracked by Google).
I have to allow every user of my site to be tracked by Google if I want to get the AMP ranking advantage.
I can’t fork AMP.
The ranking advantage is given only if you use Google’s AMP cache.
I don't think it's fair to claim that (a) applies here, certainly not like Facebook at least. Facebook makes an effort to keep user-created content inside of their platform. Google does not make any effort like that with regard to AMP, other search engines could use the AMP data just as well. Serving it from their own domain is just a technical matter.
But it doesn't do (a), either. Google hosts a cache of the content, but the original is hosted by the publisher, and Google's cache isn't exclusive. Microsoft, Facebook, and Twitter, IIRC, operate their own caches, and so can anyone else who wants to (and there's a fairly strong incentive too if you host something that functions as a high-volume portal.)
AMP makes it harder for real walled gardens to provide an attractive performance advantage to end-users, making it not only not a walled garden, but also a potent weapons against walled gardens.
AMP does (a) and (b); I don't know about (c); and doesn't do (d).
Still, I can see why people see echos of walled gardens in AMP.