# Why isn't NV-center-based quantum computing mainstream?

One can rattle off names of implementations of Superconducting Qubits, transmon qubits, etc

For example, see Physical realizations used by Google

But NV centre Qubits as in this question, Is there any company that backs and implements diamond vacancy quantum computers? have no large company spending money on it.

Any research on it is relegated to academia or the companies in stealth mode.

What about its implementation makes it unattractive?

One would think that since it operates at near room temperatures should make it more appealing? For reference See Quantum computing book by Nielsen and Chuang

Disclaimer This question is completely produced by a comment in this answer.

One of the most striking qualities is extremely long coherence times made possible by coupling NV center electron spins to surrounding nuclear spins through hyperfine interactions. Relatively recently, Tim Taminiau's group showed a 75 second coherence time for a single qubit state here. The system described in that paper uses the NV center plus 9 surrounding nuclear spins (one $${}^{14}$$N plus eight $${}^{13}$$C) to create a fully connected 10-qubit register. That's 10 connected qubits from a single NV center, very impressive!
As a final note, Awschalom (from the videos linked above) is a leading expert on this topic and runs a group at Chicago doing great work in this space. Awschalom is also Director of Q-Next, which just received commitments for \$115M in funding from the DOE, plus \$93M in private money. Hopefully with Awschalom at the helm this funding will help drive NV Center technology towards maturity.