What happened to the plot?

I’m watching for the first time — love the show (currently on 06x02) But what the hell happened starting with season 5?! I don’t mean like can you clear this up for me. Some things don’t make sense but I expect them to unravel/will look for discussion later so I don’t get spoilies. I mean this whole time travel thing. I know it was already a borderline sci-fi show, but it got crazy. And then we’ve got this meta going back in time to go back to the future and go back in time but and everyone still wants to kill each other and people die but don’t die and good guys are bad guys and bad guys are good guys etc etc. I just feel like it’s a totally different show.

I wouldn’t say it went downhill because it’s still really good. It kind of feels a lot like when the Palladinos left Gilmore Girls. Is this just my unpopular opinion?

Edit: I did see that other users post just now but I feel like this is a different discussion