A person as a person develops all his life, and if, apart from the "work — TV" link, nothing happens to him, then this development is stalled, the person begins to degrade, and new professions have given us free time, which our great-grandfathers with ordinary, not blue blood practically did not have. Depending on the workload and priorities, we can become a little bit patrician in the evenings and on weekends: to create, to have fun, to do something else besides the obligatory work. We can, but we don't always do it.
No, the TV doesn't count. In a hobby, a person is not a passive consumer of content from the screen, but a thinking creator, an active figure, and this action benefits him.
Depending on what a person is interested in and how much he is immersed in it, he can:
relieve nervous tension, relax;
switch between mental/physical / creative work;
to realize the needs and desires that remain behind the scenes in the framework of the main activity;
put your thoughts in order and catch an insight on work issues;
avoid professional reformation;
meet and communicate with interesting people;
learn a new profession;
create an additional source of income.
A hobby should not combine all these advantages, but there will definitely be some in it. Hobbies should be fun in the first place. And then development and, if you're lucky, additional earnings.