There are investigations for everything. Also for how the loading time of a website affects the possible bounce rate of the visitors. And it's hard to believe, but the bottom line is that the longer it takes a website to load, the higher the chance that the visitor will close the tab. Incredible.
The AssetCollector has been integrated with TYPO3 10.3. With this, scripts and stylesheets in Fluid files can be added to the rendering process with the ViewHelpers f:asset.script and f:asset.css. They behave similar to the renderAssetsForRequest already added in 8.6, with which you could render the corresponding code via the two Fluid sections HeaderAssets and FooterAssets.
But with the simultaneous use of HTTP/2, which ensures that the resources for rendering the website are delivered to the browser before it even knows that it needs them, a speed advantage is still achieved in conjunction with the small data size and is especially noticeable in a faster rendering of the page. It is not at all bad that the resources are not integrated into the concatenation or compression process of TYPO3, as you were used to when you integrated your resources using TypoScript.
And so you have already made a few more visitors to your website happier.
And yes, I know, I have unfortunately not yet activated HTTP/2 on this page. It's not me. I'm sorry.