Do you realise that we are years (decades?) away from viable open source hardware? You likely use a closed source processor with closed source chipset, GPU and closed source ram. And these are the building blocks, then you have the closed source integrations of these blocks

Same applies to fitness watches. Garmin happens to be one of the best (if not the best) hardware for the purpose, with a decent (not great, just decent) software that is very closed source and very closed in interoperability.

You may say to vote with the wallet… but where? Apple that is even more closed and restrictive? Huawei that deserves its own ethical discussion?

I haven’t looked into Suunto and Polaris but I would be shocked if they were dramatically different since this is their business, selling api and integrations