Not open-source nor free. So I wouldn't really call this an alternative.

At least https://baseline.is/tools/background-remover/ is free, but not open-source either.

Once you run out of free "credits", they give you a tiny image and you have to pay to get more for for full-res. For a while that was all I had as far as AI bg removal goes and it was quite frustrating.

We use it for the Zapier integration and it works pretty well. Cloudinary has bg removal transformations too but the color seemed to get degraded.

Would be happy to learn of an alternative!