I wouldn’t be so sure about bundling being an absolute anti-pattern even with HTTP/2: http://engineering.khanacademy.org/posts/js-packaging-http2.htm — Unless HTML imports solves the issues mentioned in that post.
On the other hand, loading every file individually would no doubt result in the worst possible perf IF the client doesn’t support HTTP/2, so you’d have to maintain and serve two parallel versions of your app — one bundled for clients that only support HTTP 1.1, one unbundled for HTTP/2. (Don’t forget if we are talking about slow phones on 3G, then there will likely be TONS of users using browsers that do not support HTTP/2)
In the meanwhile, it is trivially easy to split bundles at a few critical points (e.g. routes) with Webpack, and that setup works equally well for both HTTP 1 & 2. Granted, when ALL browsers support HTTP/2 perfectly, bundling is no longer necessary, but I’m genuinely curious to see how much improvements HTML imports + HTTP/2 can actually offer over the bundle split solution in the near term and whether it justifies the development overhead.