I don’t know too much about self hosting, so it might be worth asking on a self-hosting community to see the specific issues. But from my ignorance I think there are some hindrances with smaller servers and the speed of their comments propagating through the fediverse.
Beyond that I think there is something that would jump out as a bit strange to folks if every comment or post was from @username@theirLiteralHomeIP, and If they are running on a phone their IP would be really volatile which might run into issues as well.
So I don’t think there is anything fundamentally wrong individualized instances, but there are like practical issues with it. Further, it is certainly not foolproof, but different cultures of different servers has worked well in the fediverse to allow blocking posts from spaces that you don’t wish to experience. If each user had a separate instance it would be much harder to do in practice.
Again, I’m a dumb dumb, so I would hope that someone with more knowledge can clarify, I’m just speculating on what I could see being issues 😅
Seems like you just have an axe to grind about fat people. Protein is not the deciding factor in weight gain, calories are, so I don’t know why you think a link to the wiki page about obesity would be convincing that protein powder is snake oil.
Even when you coincide that it is relevant you dismiss with little justification. Also BMI is not a great metric for individuals, many that have a lot of muscle are measured as overweight because there is a lot more to bodies that height and mass.
Can you justify why protein powder is snake oil in line with the other things in the thread? I will grant that most people have more than enough protein in a regular diet, but stats about obesity says literally nothing about if powder can help your workouts give the results you’re hoping for.