Whoever expects a site to load in under 500 ms has only a vague idea about the real world, and probably never tried enabling connection throttling in developer tools.

3-4 sec TTI is to be expected from a fully static, server-rendered website delivered from an AWS CF edge through a realistic sloppy mobile connection.

Even at 5+ sec TTI you will probably have green PageSpeed with rating in the nineties if everything else is good.