It is less important that our hobbies are something that we are "not obliged to do" than that we are actively engaged in them.

Many people spend their free time in activities of passive consumption - watching TV, shopping and doing packaged, purchased "activities". The only active component is searching for the next thing to consume.

An actively engaging hobby is very different, it involves growth and learning. Many hobbies can be engaged in either passively or actively - think of the difference between a photographer who goes out every weekend to take photos and improve their technique, compared to one who spends hours researching and purchasing equipment but rarely "finds" the time to actually take photos.

The real difference between them is the mindset, and that can be applied to things you are obliged to do as well. My hobbies tend to be extensions of things that are necessary - cooking, gardening, sewing. All can be approached as necessary chores, but an approach of active engagement turns them into hobbies. Even scrolling the internet can be turned into a hobby - although I'm not sure if moderating a group and trying to learn enough javascript to automate things will make me a better person or lead to madness at this point!

I guess my argument is that it is not doing things outside of what we are obliged to that is important, it is doing more than we are obliged to do. It does not matter whether that "more" is different things, or things we need to do done in a different way.