Why calculators depend on dyficulty rather than network power?

[szuetam]

Why bitcoin mining calculators depend on difficulty rather than on some average network power +/- some variance?
Wouldn't it be more accurate and real??

[threeip]

Why do traffic websites depend on number of cars on the road at that place and time, not average speed of every vehicle everywhere?

[szuetam]

Why bitcoin mining calculators depend on difficulty rather than on some average network power +/- some variance?
Wouldn't it be more accurate and real??

Ok, I have changed my mind, now its obvious for me
Stupid question, could I delete this post? It's to late. Nothing good happens after 2am.

[worldinacoin]

Why do traffic websites depend on number of cars on the road at that place and time, not average speed of every vehicle everywhere?

That's a real good answer