I've never felt the need to 'protect' my mental health by limiting my viewing. I like to watch the news and read about what's happening in the world. I can't do much about it, though, except donations to charities and voting according to my principles.
Still, I don't want to watch all the morning, lunchtime and evening broadcasts, that would be boring, and I did feel the need to limit viewings during the worst of the pandemic, as it was so awful, I often felt very angry.
I do find myself irritated by the endless 'some viewers may find upsetting' warnings. Perhaps those (few?) viewers could choose what to watch in advance?
My 'protecting mental health' is more about finding a balance in my own life, making sure there's plenty of variety, laughter, some company and pleasure, even silliness to counteract the daily grind, chores and duties.
Alone time is a must for me, too, quiet, peaceful walks, reading, relaxing, gardening, dozing etc. - as and when I want - priceless.