Gwenpool isn't actually a variant of Gwen Stacy, her name is actually Gwen Poole and like Superman Prime she technically comes from a universe that didn't have heroes. She has the ability to warp her own identity in reality which allowed her to come to the universe of comics that she loves. She has knowledge of a lot of character histories because she read a lot of Marvel comics in her world that were historically accurate to the 616 universe. Her power to warp reality technically only impacts her and not other people, it allowed her to transport herself to the Marvel universe. In the recent series Gwen tried to figure out what she really was and where she fit in the Marvel universe, in her own mind, or in reality with Kamala's help Gwen determined that she is a mutant and she went to live on Krakoa.

I like Gwen Stacy aka Ghost Spider, because she is an interesting mirror of Peter Parker. I would say that Spider Gwen is about 10 years younger than Peter, or generally near in age to Miles. Gwen's story mirrors Peter's, she was the one bitten, and she lost her Peter when he tried to be a hero beside her and lost himself to the Lizard formula in his desperate need to help Gwen by being a hero too. I think the biggest difference is that Gwen's Peter had a lot more agency in what happened to him then Peter's Gwen Stacy did. Gwen's Peter didn't want her to stop being Spider Gwen, he wanted to be able to help her so he created the Lizard formula but just like Connor it drove him insane and Gwen accidentally killed him when she tried to stop him.

I like that Gwen and Peter can both understand the loss that the other one feels. The age difference ensures they won't ever date, and Peter can act as more of a mentor to her. It's funny but I think some writers would prefer that Gwen and Mary Jane from the same universe may end up as a future couple, which would be a fun reflection of Peter and MJ.