A couple of holdouts? Hardly. Capcom uses the RE Engine. Released ~4 games with it in the past three years. In fact, SF6 went from UE to RE Engine. Death Stranding 2 is Decima. Id still uses IdTech, and that's never changing. Ubisoft still uses Anvil, and Outlaws was Snowdrop. EA still uses Frostbite. Bethesda continues to use their crappy engine, which I forget the name of. FromSoftware will likely never give up their engine, which has been used for Elden Ring and its successors. There's more that I can't be bothered to look up.

Swinging back? Was UE used more widely in the past than it is now?

I heard a great perspective on this from a Chinese developer. The reliance on outsourced engines like Unity or Unreal isn't just driven by the high costs of in-house development and yearly upgrades. The real issue is career mobility.

Knowledge of a proprietary engine is completely locked to that specific company. They pointed out that Unity and Unreal became industry standards simply because of the dynamics of changing jobs. I fully agree with that assessment.