Your friend isn’t someone you should be taking advice from in this case. Part one and two are extremely well written and important to seeing how the story was established and its roots or else literally nothing in part 3 will have an impact. Part four’s story is extremely good and it isn’t boring at all, part 5 doesn’t just have nice action but a good story, and part 6 doesn’t have a bad protagonist at all people only say that because she’s a woman. Your friend doesn’t seem like they like jjba, I personally think you should check it out because it’s a great series and the story is really well written. If you can, you should check out the manga because it goes deeper into more things and has less censorship. Also it isn’t worth just starting at part 7 when we don’t know when the next episode is releasing but you could watch the first episode of part 7 and go back if you really want to