"Agree" This game was not optimize for PC, I think someone did a fix and can improve your framrate by modding https://discourse.differentk.fyi/t/horizon-zero-dawn/224?fbclid=IwAR3oTa1-y7XlGENc_m4cXSRLAfQgHf0Ou7JuvTe5loah8_9CD1lplp3Ce0o Check this link I hope it will help.
I think the problem with laptop gaming is thermal throttling. With the limited design, when running in full load for a long time it is gonna cause some of these problems.
At the same price point, I would say PC But as mention above, if you are already familiar with Mac you should go for it. Also without budget include I think no one can come up with specification