I had a work supplied Lenovo tablet with a standard brick charger but it did support and work off 45W PD.
My 18W Huawei tablet has an accidental 18W PD, it is meant to be a proprietary charger but the supplied brick says 9V 2A which is one of the PD modes, and it works.
Interestingly for someone looking to lower cost, this tablet like many will accept 5V 2A. The issue with that method is the Amps, Current, is higher so a longer cable loses energy much more. For a given Wattage, energy loss in the cable is to the square of resistance times Amps, so if you increase voltage to lower current, you disproproportionately benefit on more energy getting to the end. Crudely, resistance is linear on cable length (not totally) so if you stick with 5V rather than 9V you need to use a shorter cable.
Today I was sat some distance from a wall socket and using my 2016 >3 years Powercore 26800 which outputs 5V 2A and my tablet was slowly discharging on that, so I dug out my USB-C meter and saw the input to the tablet was 5V 0.8A, off a 6ft thin Anker cable, so I swapped it for a 2ft cable and I got 5V 1.8A.
So via just plugging a very old charging technology, but just keeping a shorter cable, I could keep a big tablet charged.
I am seeing these 6ft cables and seeing people look at “high speed charging” and not sure they realise these are in opposition. A short cable is its own form of “power delivery”.