What’s the alternative? We either don’t create this technology at all or we do and accept the fact that it’s going to involve a lot of trial and error. You don’t just skip all that and jump to the final product. There’s only so much you can test on animals which exactly isn’t the most ethical thing to begin with anyway. At some point you’re going to need to stick it in a human brain.
The first heart transplant recepient died after 18 days. Should we have not done that either?