At $6.99/month, what family with kids under 12 years wouldn’t subscribe?

The low price is an interesting point. If Disney thought they could compete directly with Netflix, they'd probably price themself just slightly cheaper instead of much cheaper. By pricing themself this cheap, many existing Netflix subscribers will be willing to subscribe to both at the same time. If they were the same-ish price, many users would probably choose just one of the two to subscribe to.

I'm kind of interested to see if the readers here are changing media viewing habits... Cutting back? Watching more? Cutting cable? Paying for multiple streaming services? Or none?

I subscribe to Netflix all the time, and other streaming services some of the time. For example I'm currently subscribed to HBONordic, because I wanted to see Game of Thrones. I'll probably cancel is when I'm done watching Killing Eve. Last month I bought a month's subscription to a service named Viaplay, because I wanted to watch Infinity War before I saw Endgame in the theatre, and Viaplay had exclusive rights for it in Norway. I'll probably do the same with Disney, subscribe for a month when I want to binge a show or see a particular film.

At the moment I feel Netflix is the only service worth subscribing to full time, because they have so many good shows, and distribute them around the year. HBO has just three shows I'm currently interested in, Amazon Prime has three, Disney might have zero.