" we pay really attention to performance and it's a dream"

Does this include in low-connectivity environments? The biggest advantage of api-driven PWAs is that it supports no-connectivity and low-connectivity nicely, assuming you put effort into enabling it (having an offline cache of data) and having loading indicators visible to the user. With a regular page-load-driven application, if i'm on 1 bar of 4G I might get the TTFB for a page load and then be waiting as page assets slowly load in, staring at a white or half-blank screen the entire time.