Hass.io on Raspberry Pi Question

Just have a very basic question. When looking at the install instructions for hass.io (https://www.home-assistant.io/hassio/installation/) the versions for 32bit Raspberry Pi are recommended, not 64bit. Both Raspberry Pi 3b+ and 4b+ support 64 bit OS. For the life of me I can not figure out why the 32bit option is recommended. Is it because the max memory on Raspberry Pi 4b+ is 4gb and that can be fully address with 32bit address space or is there anther reason?

Well for one, the GPIO integration does not function in the 64bit version and it looks like no one has the time to fix it. The issue was closed because there was no activity, not because it was fixed:

There are probably other issues too.