Her career path is following the same trajectory as Alanis Morissette's - huge debut, then slowly tampers off with each subsequent release. Alanis didn't win a Grammy after her second album, and that was 16 years ago. Gaga hasn't won one since her second either
Alanis struggled to maintain mainstream relevance because she was niche. She's part of the Shania, Norah, Amy, Duffy, Dido and probably Adele and Lorde, crowd who are huge for one (or two) albums but fade when they won't/don't adapt to new trends.
You have to adapt to survive in pop. Thankfully, Gaga can. Once she gets over herself and plays along, she'll be fine.