I started doing 10,000 steps a day religiously about 6-7 months ago and I wish I'd done it sooner. It's been hugely beneficial to me personally.
I've found it something achievable I can do every day, regardless of how I'm feeling. Being consistent in exercise is a hugely beneciL and this is an achievable level of exercise that research shows has clear health benefits.
From a personal point of view, having a target to hit every day, and a reason to get out of the house ever say and walk has been very beneficial to me. Having a step counter and a clear goal every day has been satisfying and I feel a small sense of achievement each day when I hit the target. In addition I have found my mental health genuinely improved. On bad days, just getting out of the house and walking completely turns my mood round.
I personally would strongly recommend walking 10k steps a day. Even if you do vigorous exercise a few days a week, on your "off days" do 10k a day.