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)