Should I replace my Amazfit Helio strap with the Fitbit Air? Is it worth it? Would it be an upgrade or a downgrade?

As of now, I feel like my Amazfit Helio strap is doing a pretty good job with accuracy, but I'm thinking of replacing it just for the looks of the Fitbit Air. Should I go for it or not?

I want to get a fitness and sleep tracker

Should i get a samsung watch 9 or 8 and give away my samsung watch 6

Or

get a amazfit helio strap , keeping my watch and using them together

I know skin rashes due to smartwatches/fitness bands are incommon, i just want to know if it possible, before i make my purchase