Returning player, should I start a new acc?

Hey everyone. I've been looking to get back into gacha games and I remembered Arknights. I had a one year account from the very beginning, so I have stuff like Savage, Nian and limited things from the first year of playing. So I'd be coming back to the game after like 4-5 years.

The thing is, it has been so long and so many new systems have been added, changed, the UI even. Not to mention story, don't really remember much about it. I feel like it would be best to start a new acc, so I could get used to everything again. That's what I did, been playing for a few days and I've been having a blast. But I'm worried I'd be missing out on the unobtainable content that my old acc has.

So mostly, I just want to discuss with the vets or new players here. Would I be missing out? Could I still obtain operators, skins later if I continued to play? I like starting fresh and that's what I'd like to do, but I wanna hear y'alls opinion. Thank you :Dd