grammatically well established singular they/them

I mean, historically it’s well established, but you can’t deny that language has evolved in many places (at least in America) that they/them feels plural. I’m not saying they/them shouldn’t be gender neutral singular pronouns, but in the dialect I was raised, it only feels correct in indeterminate situations, like “whoever stole my bike, I hope they get arrested.”

Obviously language can continue to evolve where singular-they feels correct in any scenario, but if you’re talking about “much easier” then that includes the random rules people collectively hallucinate.