My point is, it seems like once you have put in place the habits and technological solutions necessary to store fitness data, it actually takes more effort to reduce the resolution of older data. I'd rather have data and not want it than want it and not have it, but then I am an almost pathological hoarder so maybe it's just me.
I am not a hoarder as a counterpoint. I am always looking at ways to reduce what I have and remain focused. I lived with a hoarder in a house full of trash and don’t want to be that person to someone else. He also had 4TB of photos and videos that needed to be dealt with.
I think at the end of the day my life can probably be compressed to a few images and a few paragraphs…
Some of them might be historically interesting enough to preserve on Wikimedia Commons, for example if they depict places that look very different today, or stuff that you don't see in everyday life anymore.
I am a big proponent of not leaving my kids a pile of trash to sift through. See my other comment on this matter for background.
They could just have it on a portable drive and look through it whenever they want. It's not like they have to catalogue every picture :)
Looking at my device storage, I have 91Gb online for 5 people. That’s everything we have ever done. Because we care enough to look after it and curate it.
As per photos you don’t need 11 pictures of those muffins you baked in 2003. One will probably suffice, if you even care about them 18 years later that is.
The same goes for health data. But overall trends over 20 years are really useful as you get older. Expected decline is inevitable but unexpected decline may be indicated earlier and result in some preventative action to improve your quality of life. There are a lot of long term metrics appearing in Apple health like walking stability on that front.
On photos, I’m not sure what I’d do with 200,000 photos. I have 7,623 which span 4 generations and 125 years at the moment. I spend a lot of time curating these photos, adding metadata, editing and pruning garbage. They are all managed with Apple’s native Photos app which is good enough for the job (non destructive, sqlite DB underneath it, easy to back up)