The devices need FDA approval and some safeguards. A neurosurgeon needs to assess the risk vs benefit for the patient and they need to come to an agreement on whether it's the right treatment. Problems with these devices are strokes, bleeds, infection, swelling in the brain, etc. which while fairly rare aren't insignificant.

Aside from that general statement on risks of brain implants and brain surgery, the other big issue is whether or not they will be supported in 10-15 years or will Elon Musk flush that company down the drain as well? There was a company making implants that helped patients see that just shuttered it's doors and said "whelp, sorry folks, no one can help you with your implant now".