I have a dev http/2 server that is serving my app locally, amounting to 271 module dependencies. It takes about 400-500ms to load everything and startup the app. The implementation is trivial and without errors, every dependency can locate its assets because it sits at its real path, sourcemaps etc.
Switching to Early hints/Link: it becomes 4-5s and even with all of the modules cached, it doesn't get less than 2-3s. So this could be an implementation difficulty and might be improved, but it is still a non-trivial overhead.
Now the only viable solution becomes bundling, even with esbuild the improvement over http/2 push is marginal. But now there is an extra build step that before was handled at the HTTP layer by "push". The files are bundled to a single file, so they no longer can access their assets relatively to their path, since they have changed paths. Workers etc. have the same problem, import.meta.url no longer works and so they can't be located. Not without various steps of transformations and assets handling, and there'll always be edge cases where those are going to fail. Certainly not composable across domains/projects since by bundling they become hardwired to their environment.
Push doesn't have these problems. So, it's a step backwards IMO to remove it. Without "push", the only viable solution becomes to use 3rd party bundling tools for any non-trivial work that exceeds a handful of dependencies, where with "push" you could deploy the exact structure of the code as it was. Bundling makes source code and the web less open and less accessible and with this change there is no other solution. Early hints are fine when dependencies are less than a dozen, but it becomes much worse as they grow, leaving you with no choice than build steps/bundle steps, instead of simply uploading the directory of your source code to the http/2 push server leaving the structure intact.