Won and done: Why ‘The Voice’ hasn’t produced a big star in its 10 years

Once Alisan Porter was the last singer standing on the 10th season of “The Voice” in 2016, she won — as all of the confetti-doused champions do — $100,000 and a recording contract.

But after that pitch-perfect ending on NBC’s singing-competition juggernaut, her pop-star dreams soon turned into a nightmare. “It was sort of like, ’I got this record deal, but what do I do now?’ ” Porter, 39, who became the first winner for original “Voice” coach Christina Aguilera, told The Post. “Once you win, they’re on to the next season within two months and you’re a has-been. And I was, like, terrified that I wasn’t gonna use this momentum to make it in the music business. It was definitely not what I had expected.”