> hybrid power unit closer to 50/50 split between ICE and electric horsepower

Fun fact, at those ratios it would make a lot of sense to use an electric continuous variable transmission (eCVT) - connect the engine and the motor with a planetary gear set to the wheels, done. The electric motor spins backwards when going slow and forward when going fast. Those eCVTs can be lighter, more efficient an deliver more power across the entire range. But they're illegal in F1 - because they make the car sound boring.

> But they're illegal in F1 - because they make the car sound boring.

I can confirm, my CMAX has an eCVT, and the engine noises are boring. Either it's off, or it's running in a pretty limited range, you can get a bit of fun rev increasing noises if you drive it just right... but mostly boring. My 81 VW Vanagon is much more fun to drive even if it's objectively worse at everything in terms of acceleration, top speed, wheel slip, etc; although the turning circle on the cmax is garbage, so the vanagon wins there. The VW makes fun sounds as you go from low rpm to redline several times as you work through the gears, and the cmax is just droning along.

How Toyota's eCVT transmission works: https://www.youtube.com/watch?v=ppyK3ZlUbtM (Nerd snipe warning: the Weber Auto channel is brilliant and has lessons about all kinds of transmission and engine types).

When it comes to something like F1 I think it's OK for efficiency to not be the top priority. Road vehicles absolutely should be as light and efficient as possible with strict limits on pollution (including noise). But it's OK for society to have a few things like F1 that are just for fun. We just don't want everyone to be driving F1 cars around their neighbourhoods or have an F1 race every week.