The input situation is dreadful and I couldn't stand the delay with AirPlay2 either. However, combined with an AppleTV 4K (2nd gen upwards), HomePods can be us

The input situation is dreadful and I couldn't stand the delay with AirPlay2 either. However, combined with an AppleTV 4K (2nd gen upwards), HomePods can be used as HDMI eARC devices. This enables playing sound without delay from any HDMI output. In my setup I use an eARC capable HDMI splitter and a $10 Thunderbolt to HDMI adapter to create an audio device for my mac that has virtually no delay. The video output of the HDMI adapter is set to just mirror my first screen, which avoids additional video processing load.