even having LTE I notice significant battery drain on my pixel (not that Google allowed me to use 5G)
So no it’s a general problem with the modem for that, it’s just drains quite the battery.
(I do use a Pixel 7, @SpunkyEatsYou didn’t mention which one they have).
The only solution I found unfortunately is to just remember to turn it off when you’re on you local Wi-Fi.
I also don’t recommend Enabling LTE Only as it means if your phone needs to fallback, it simply won’t and that may be inconvenient (If you don’t have that problem, that’s fine but for some carriers it’s probably necessary to be able to fallback to 3G if not in general for some areas you can’t reach an LTE Network.)