Don't know what your expectations are but my 8 Pro does 30-40 hours on a full charge. 6.5%/h during screen-on, 1.5%/h during screen-off. To me that's pretty good. If the move to manufacture future Tensor SoCs at TSMC is true, the first one made there would add a measurable boost to battery life too.
They also have smaller screens which decreases the power consumption, typically balancing it out. The power consumption during screen-off would be the same, so there would be slight hit there from the smaller battery.
There's also difference between the Pixel 8 and older series in that the 8's Tensor is made on a smaller process node which makes it more power efficient than 7 and 6.
I have a 7a. The battery life is enough to get Mr through a shift at work and a half hour charge 12 hours later gets me through the rest of the day.
I got a case with a magsafe on the back and bought a little magsafe power bank. Wireless charging with it puts my battery at a standstill, and I can use it to charge my ecig and my headphones, so for £15 it's useful.