Ask HN: How are voice cloning reels like fullstackpeter created?

I have started seeing reels from https://instagram.com/fullstackpeter which explain programming concepts in the voices of Peter and Stewie.

There are also some other Instagram accounts specifically made for Indian audience like https://instagram.com/fullstackraju as well

My question is, are they using ElevenLabs? Is it feasible at that scale? If not, what other options do we have?