Fair point. Once packed into the <head> is better.
There's still a care to be taken when using <style> tags in development. I know developers don't always respect development performance (because it's just development), but that performance can still matter: to you in your debug cycle time, and also sometimes bad performance in development masks bad performance that will impact production (and developers don't notice it because it "always performs that way when I test").
For that reason, bringing the aside somewhat back on topic, I often prefer to use minified stylesheets/JS in development and trust sourcemaps to do their job when I need to debug them.
There's still a care to be taken when using <style> tags in development. I know developers don't always respect development performance (because it's just development), but that performance can still matter: to you in your debug cycle time, and also sometimes bad performance in development masks bad performance that will impact production (and developers don't notice it because it "always performs that way when I test").
For that reason, bringing the aside somewhat back on topic, I often prefer to use minified stylesheets/JS in development and trust sourcemaps to do their job when I need to debug them.