As mentioned earlier, the browser handles HTML from the server in a very performant way by default. It will break up parsing and rendering of HTML in a way that avoids long tasks, and optimizes the amount of total main thread time. This leads to a lower Total Blocking Time (TBT), and TBT is strongly correlated with INP.

Source: Client-side rendering of HTML and interactivity -

I’m more and more dubious of JavaScript thick-clients. This is Google writing this, and presumably with involvement from someone on the Chrome team.