Because any regrowth solution would be quite expensive, time consuming and prone to problems.

It would likely be performed by surgeons and monitored by orthodontists there couls be multiple teeth comming out, missaligned and so forth.

I'd much rather do things the old fashion way than risk all sorts of problem down the line, have multiple trips, wait months upon months for my teeth to regrow.

As a last resort, or instead of an implant, yeah, sure! But afik, the money you pay for materials are smaller than the surgeon's fee, so I see no incentive for a surgeon not to give you natural teeth if he could.

It could be that he'd make more money that, way, less checkups and so on.