Why so much analogue?

You won't hear interference in amplified signals being distributed to a in ceiling speaker short of running it parallel and within a few inches of the power feeding the oven or dryer for a long distance. The maximum runs you will encounter in a residential house are less than 100' (33meters) and that's in a rotten installation point. A well centered distribution closet is more than likely going to be closer than 50' (15m) for your longer runs.

Now these distances are for average homes, not a McMansion where 100' runs may be typical. I've got whole house audio and my shortest run of speaker cable is about 10' and my longest is about 60'. I ensured I didn't run parallel to any power lines in the walls and you can't hear any hum. It's just not that complicated at the distances involved in whole home audio.