Excellent analysis by Tim here:
Good frameworks should provide a better starting point on the essentials (security, accessibility, performance) or have built-in constraints that make it harder to ship something that violates those.
That doesn’t appear to be happening with performance (nor with accessibility, apparently).
What is clear: right now, if you’re using a framework to build your site, you’re making a trade-off in terms of initial performance—even in the best of scenarios.
Some trade-off may be acceptable in the right situations, but it’s important that we make that exchange consciously.
Do yourself a favor and tuck into the numbers here. He presents a substantial amount of very useful information.