Google Pixwl XL allows for slower charging, if a non USB-C adapter is used.

From the support area at Google on the section concderning charging. See the suggestion #2 for your concern:

Which power adapters and cables to use

1. Pixel phones use USB-C with USB 2.0 power adapters and cables.
2. To charge your Pixel phone with a USB-A power adapter, use a USB-C to USB-A cable. This will charge your Pixel phone more slowly than USB-C.
3. Other Android cables and power adapters might not work with Pixel phones.
4. Pixel phones can't charge wirelessly.

Google Pixel XL allows for slower charging, if a non USB-C adapter is used.

From the support area at Google on the section concerning charging. See the suggestion #2 for your concern:

Which power adapters and cables to use

1. Pixel phones use USB-C with USB 2.0 power adapters and cables.
2. To charge your Pixel phone with a USB-A power adapter, use a USB-C to USB-A cable. This will charge your Pixel phone more slowly than USB-C.
3. Other Android cables and power adapters might not work with Pixel phones.
4. Pixel phones can't charge wirelessly.