From what I gather, it seems like this would be a good choice if a portion of clients are on low end devices and it is more of a MPA/SPA hybrid - not a full blown web app. A lot of E-commerce and informational sites do fall into the MPA/SPA hybrid bucket.
If you really are making a web app (think dropbox, cloud based enterprise software) I think you'd reach a point where there is so much interactivity that you are essentially shipping Preact, custom component JS, and just a little bit of static HTML. The latter bucket is the only one which saves the user network and parsing time (and I doubt much of it.) I'd still go with a properly chunked SPA for true web apps.
If you really are making a web app (think dropbox, cloud based enterprise software) I think you'd reach a point where there is so much interactivity that you are essentially shipping Preact, custom component JS, and just a little bit of static HTML. The latter bucket is the only one which saves the user network and parsing time (and I doubt much of it.) I'd still go with a properly chunked SPA for true web apps.