I watched some of Suits a few years ago and whilst Meghan is perfectly competent in her role, I don't think she is what made it successful. I found the banter between Harvey and Mike and the relationship between Harvey and Donna was the heart of the show.
I can see an argument for saying it's popular now because of Meghan's increased profile.
I think it is always interesting when popular shows have casts that don't really go on to do anything as successful. Sometimes it's the specific blend that works but individually they don't have the same magic. I see Suits in general as one of those shows.