Spirit is a guessing game
There are 2 types of games : Luck-based and skill-based (of course mostly ever game has both but one is more heavy then the other). In luck-based games you sometimes say "Well, I was unlucky, that's why I lost." Hearthstone, for instance but in skill-based games you lose because you are bad. Git gud etc. So, what happens when you combine both ? If you ever played TF2 and encountered "random crits", you would know.
When I play against Spirit and I win in a chase, I never say "Yay ! I was the better player !", it's always "welp, I was lucky". Since Spirit can stand at a pallet and wait until the end of time, you never know if she is phasing or not. You can guess if she is phasing. So for the sake of the scenario, let's say she is not. If you guess that she DID and you slow vault the pallet, you get hit. If you didn't, congratulations ! You won with luck ! This is not fun people.
I heard the argument that "Spirit and Nurse are the only killers that can counter a tournament team !" I won against a tournament team as Clown with 2 reload addons. Now, they are too powerful, I agree about that but that doesn't mean that a killer can be busted AF just so it can counter a team. Spirit AND those teams should be nerfed.
I also heard the argument "She is only good at 1v1s !" No she is not ! She is especially good at 1v1s but she has a lot of mobility too. With tracking perks, she is counterable, yes, but with luck ! If you are not lucky, you die.
For the record, I don't think Nurse is an OK killer. Just like Spirit, if she is in the right hands there is little to no counterplay. Her power is incredibly strong but at least she requires an ungodly amount of skill to play. If she didn't, she would be "More powerful and stronger Spirit".
So, what could be done ? Add a phasing animation so that she stays still but you know that she is phasing. This would open up mindgames where you can actually do something. Oh, by the way, Stridor is way too powerful on her. It's not like "STBFL and Demo's shred" since that is combo, this is busted AF. Do something about the perk or about the killer in that.
TL;DR : Spirit is lottery, you win based on luck. That is stupid.
Edit : Read the goddamn post, people. I see some many people commenting about "all killers having luck", literally read the first sentence in brackets. Spirit has way more luck than every killer and I said this a million times, in the post like I am doing right now AND in the comments ! Read before you speak.