Whereas Marvin Gaye's heirs' successful litigation against Blurred Lines is very concerning (see: https://www.jonesday.com/en/insights/2018/07/blurred-lines-b... ), although as has long been the case with copyright litigation in the USA - it really all depends on the jury !
Personally, when I listen to Marvin Gaye's "Got To Give It Up" right next to "Blurred Lines" I really cannot comprehend the jury's result. I guess they both employ a cowbell very prominently? But I wasn't a member of the jury, so it wasn't up to me. I find the Katy Perry result to be at least a little bit of a close call based on my own listening.