[PP-1] Disable "Bandwidth Optimization" when serving with HTTP2

Moving to needs more info. There's also the issue that aggregation and minification are linked.

On top of this, the sheer number of elements that CSS and JavaScript would add to a page would increase the amount of HTML to download and parse - it could be hundreds.

I think we'd be better off looking at 📌 Use the asset library dependency tree to improve CssCollectionGrouper & JsCollectionGrouper Active and revisiting this only after that issue is resolved.

+1!

The general advice on the web as well as 99% of articles on this subject do not apply to Drupal, because Drupal is extremely modular, with each Drupal module able to add 1 or more CSS/JS files, and potentially hundreds of installed modules… resulting in indeed hundreds of CSS or JS files, with each one tiny.

I have yet to see any data at all on how hundreds of tiny CSS/JS files would impact front-end performance on HTTP/2.

But given that each even for far fewer and far larger files, it wasn’t even feasible stopping bundling and relying entirely on H2 until at least a few years ago, it seems unlikely the increase in overhead could ever be sufficiently compensated 😅

(The only way that could IMHO conceivably happen is if at least we let asset-library-level bundling. That would then also result in a nice simplification of the asset handling logic. But … on its own that’s probably not worth it either. And it likely still results in a performance regression.)

There is the ADVAGG bunder module where one can set a number of files it is aggregated to, meaning one can set it to eg. 15 files which is good trade-off for HTTP2. I think something similar in core would be very beneficial.