I think it depends… Some days i get a bad losing streak other times wins. This is also a mixture of either me doing really well or not being able to do anything and just rolled by the enemy.
I would like to also think that possibly maybe region comes into play? I usually play on AU servers and the quality of games are much worse compared to US or JP/KR games in general might be a placebo effect but I havent got as many bad strings of games ever since i switch servers now.
End /early of season is also typically the worst time to play even though ranks doesnt reset until S9. But even QP is kinda ass too.
Someone made this a while ago https://www.reddit.com/r/Overwatch/comments/187gh61/numbers_of_battle_pass_legendary_skins_for_each/
but pharah and widow definitely feels like they got the most shop/bundle skins cant say for certain since I personally just grown accustomed to just ignoring them (shop skins) until I broke and got the LSF skins lol.