I use a Fitbit, an oximeter and a watch. This works for me. The Fitbit is quite accurate for steps, gives me a read on my sleep, and is a good reporter of my exercise. The independent testers of some of the all in one units indicate that the oximeters aren't very accurate or responsive, so I rely on a good oximeter and a Fitbit.

As you know, few models have O2 sensing anymore. Active HR should be considered a minimum. Follow the reviews based on preferred features and your budget.
This is one of the few tech items with a large user base. Users complain loudly if features don't match up and perform well or if cost doesn't justify the actual utility. Even wearing an inexpensive model beats guessing how many steps you've taken around the grocery store. Stay safe and be well

I use A MI 5 smart watch made by Xiaomi they are about half the cost of cheapest fitbit. Have used both and prefer the Xiaomi over the fit bit. Charge last for about 2 weeks.

I also use a fitbit. I find it keeps me focused and dedicated to getting my exercise. I find the resting heart rate very helpful as a guideline of how hard I'm pushing myself and an "indicator" of how I'm feeling. Sounds weird but if I'm being active and my resting heart rate #'s starts rising, it's a clear indicator for me that I'm fighting something off and I react accordingly. Good luck and hope you find something that works for you!

Not sure if it helps i some time ago looked at these watches then decided on a finger monitor like the doctor use. Takes heart and oxygen level seems
To work for me and it’s cheaper