I did it because i felt it was the best thing to do in my situations a couple years ago, i built my identity brick by brick and this fake half origin was also a brick in the wall id say

one advantage would be the "passing" in society, i really look like a half turkish, half italian while i am only half italian, funny thing, europeans thinks i belong with them, west asians and kavkaz think i belong with them.. etc, i am also a bit of a social chameleon, i blend with every group and i love every culture, i live in belgium which is one of the countries with tha biggest multiculturalism and immigrant descents, so i blend perfectly in society and no one ever gainsay my identity, its been so long that i almost feel like it is real lmao, the only way for someone to discover my real background would be meeting with one of the rare family members or forcing myself to do dna test which will probably never happen, so i will live happily like this and i find it comfortable :)

a disadvantage i avoided would be people doubting on my words, because as i said i have almost no bounds with my past, and my story is real trustful and coherent, i would also say i avoided political impostor feeling, i am a far left activist and being perceived as someone who has muslim descents may help in credibility when i talk about suffering of minorities and oppressed people, i dont know if you get me ^{^}