I don't think changing a job is easy. I hate the current tech interview gauntlet. I actually put off switching jobs for like 3 years at my previous company even when I really should have left in part to avoid going through that (also some other reasons, like having no office to force RTO during the pandemic).
But it did seem to be more effective and easier than some other options at getting me out of the rut I was in at the time. Also when I actually pulled the trigger and put myself out there on LinkedIn, it ended up being easier to find a new job than I thought, although in fairness that was also in 2021 when tech hiring was still white hot.
By change friends, I just mean start going to meetups and meet some new people, find a couple other people you might like hanging out with. They can introduce you to new experiences that way. I've been doing that myself recently. Went to a dinner meetup with 8 people I've never met before just last Friday night, and a meetup at an Oktoberfest meetup with mostly new faces the week before that. And went back to a book club meetup I hadn't gone to since before the pandemic the week before that (and read a book I'd been meaning to read for a long time for it).
Changing which hobby you focus on isn't that hard either, unless you're trying expensive hobbies, but even then there's usually cheap ways you can experience them, like take a few lessons, or watch Youtube videos about it. But for me this wouldn't be enough, I already bounce around from hobby to hobby anyway. For someone who had only had one main hobby focus for most of their life though, or doesn't really have any hobbies outside of work, this could be enough to get them out of a rut.
Again these are ideas for changes and I only suggested changing one of them, not all of them. Some changes will be more suitable for someone based on their current situation than others. And really it doesn't even have to be these, they were just ideas. The main message was just 'Change something significant enough that you'll notice it'.
Like changing your breakfast cereal is likely not enough to get yourself out of a rut in life. But working out three times a week for six months and you start feeling better and healthier? That could be enough.