I think Honda can go back to the glory days of McLaren-Honda of the 80s-90s, but it will take a serious attitude change from them. They no longer had any of their old F1 Engineers working, they lacked expertise and they've refused to bring in external people to help them get back into the sport. And they're really struggling for it.
Ultimately, I hope Honda does get it together - it's better for the sport with more of the auto-industry involved. But it will require a big culture change from them for them to enjoy success in F1 again. And it really is embarrassing how bad their power unit has been for McLaren. If a car struggles to even make it through testing because of its engine, there will never be suitable testing for the chassis. The focus will always be on increasing the reliability of that power unit... and that's not even addressing the complete lack of power they're facing. I think Alonso needs to bail ship ASAP though. He doesn't have a lot left in his career, I'd like to see him do a bit more than struggle to finish races as he winds his career down.
So how would we rank the cars right now? I think it's tough to tell who's better between Ferrari and Mercedes, Red Bull is comfortably third IMO, then I think it's pretty up in the air so it'd be interesting to see how we all rank them... and at the back of the pack Sauber and McLaren, in that order. For my middle of the pack: I'd go with: Williams, Force India, Toro Rosso, Haas, and then Renault.