Like others, I disagree with some recent Supreme Court decisions. But recent Supreme Court decisions are not a power grab so much as a conservative view that the Court is taking where it will only interpret laws based on their text and what Congress actually passes.
The alternative philosophy, where the Court interprets what is broadly aligned with general Constitutional and legal ideals, has lost out and will be out of favor for quite a while. This pushes much more power to the legislatures, but does not consolidate power in the courts.