Yeah but this is Intel, they're not capable of doing something the most efficient way possible. E cores use less power than P cores, but that doesn't mean they're very good at getting the job done using the least amount of power. Currently (using Intel's management) 12th and 13th gen start a task on the P cores, and if it runs for longer than X time it gets shifted over to the E cores where it can churn away. Meteor lake has 3 stages of things since there's P cores, E cores, and LP E cores. If I remember right Meteor lake starts a task on the LP E cores, then shifts it to P cores, then shifts it to the E cores if it's taking too long. But Intel likes to blast the power away with turbo boost and runs the E cores way past their actual efficient zone unless you wrangle them back down. Sometimes it's faster to blast the task away on the P cores then return to idle, other times letting it churn away on the E cores forever is the best way.

Also all those extra cores being active still uses power. So if you went from a 4 core CPU to a 4 + 4 cpu now you have all the same power draw as the old one, plus the extra 4 efficient cores sipping at even more power. I think that's where 12th gen really suffers the most.