This is a common topic in some genealogy groups on social media. In some groups, it’s a banned topic as both sides dig in to defend their position. For the public supporters, the attitude tends to be genealogy is a shared experience. However, most genealogy websites have no problem adding from other public trees without verifying the facts from the other tree. In many cases, the original tree is so fully of wrong facts to make it meaningless. Yet, many people have no problem adding the erroneous information without validating the truth of the information. My suggestion is go with the choice you think is correct. One friend has a public tree with relatives he has documented and a private tree for relatives he has not documented.
From the private supporters, it tends to go the other way. They don’t want people copying what has not been documented as fact. The above does not include Not the Parent(s) Expected (NPE) that often make the tree useless. Go far back enough and you will have NPEs show up. In some cases, a child realizes that Mom and/or Dad are not the parent(s). A few of the groups I belong have regular posters that find our one or both parents are not the expected parents, usually through DNA testing. They often get mad when someone adds a relative connected to the wrong relative.
I always warn people that photos are a poor example of determining if a relative is related. I saw a blog post where the daughter assumed she wasn’t related to her father because they didn’t look like each other. She later had a DNA match on her father’s side that showed he was the father. At very close family levels, you should match everyone. In this case, the father assumed because the daughter looked like someone else, the other guy was her father. Turns out, the father was wrong, but died before finding it out.
DNA can be wrong. Starting at 3rd cousins, you won’t match 10% of 3rd cousins. By 4th cousin, you won’t match 50%. By 5th cousin, you won’t match 90%. At 6th cousin, you won’t match 98%. Cousins marrying, endogamy, can change the odds. My father’s parents were from a small community in North Carolina that was out of the way. He married my mother while in the Air Force so that broke the chain. In each case, my parents had a lot of endogamy in their separate trees. Not quite as bad as mother’s parents were from two different parts of the country. Her father was from Kansas. Her mother had deep Acadian roots in Louisiana and Mississippi.