AMP puts 100KB of JavaScript in the initial render path, and a bunch of CSS. That doesn't mean that other sites cannot be worse but it means that there's no way to make an AMP page which doesn't require transferring at least that much data.
I notice this fairly regularly in marginal network coverage (subway tunnels/platforms) where AMP pages load no faster than any well-optimized site unless the stars are aligned and you actually get a cache hit.
I notice this fairly regularly in marginal network coverage (subway tunnels/platforms) where AMP pages load no faster than any well-optimized site unless the stars are aligned and you actually get a cache hit.