To do anything to a device, you have to interact with it.
The ways to interact with a Pixel smartphone are the touch screen, the power & volume buttons, the USB-C port, Bluetooth, WiFi, and the cellular modem.
All of the professional data extraction tools use the USB-C port to do their interacting, so setting it to charging only essentially ends their ability to attack the device right there.
Maybe, if they could get the phone into a lab before the reset window (18 hours by default), they could manage some kind of direct hardware interface to bypass the USB port being blocked. I don't know enough about the possibilities in that space to have a credible opinion on viability.
As a practical matter though, unless you are facing a very well resourced threat actor who knows you are running GOS and has already prepared in advance of seizing your phone, bureaucracy and logistical considerations will get you passed the reset time window so it will be BFU.
Realistically, law enforcement seizes your phone. Then they need to get that phone back to the station, entered into the system as evidence, and transported to the technical unit. If they haven't already done so then (in the US at least, your mileage may vary in other jurisdictions) they need to get a warrant to extract your phone. Then, once they have the warrant, the technical specialist needs to get around to attempting the extraction. Then, having realized that Cellebrite isn't working they likely contact them asking for advice. Then comes contacting a specialized lab to attempt more exotic methods of extraction. Absent an existing relationship that means contract negotiations and getting the expense approved (such work has a price tag in the tens of thousands of dollars). Then comes transporting the phone to them.
The 18 hour window can get used up very fast. If its a serious concern, lowering it down to a few hours is perfectly viable and would make any such attack a practical impossibility.