So the basics:

- quantum physics are real, this isn't about debating that. The theory underpinning quantum computing is real.

- quantum annealing is theoretically real, but not the same "breakthrough" that a quantum computer would be. Z-wave and google have made these.

- All benchmark computations have been about simulating a smaller quantum computer or annealer. which these systems can do faster than a brute force classical search. These are literally the only situation where "quantum supremacy" exists.

- There is literally no claim of "productive" computation being made by a quantum computer. Only simulations of our assumptions about quantum systems.

- The critical gap is "quantum error correction", proof that they can use many error prone physical qubits to simulate a smaller system with lower error. There isn't proof yet that is actually possible.

This result they are claiming, is they have "critical error correction" is the single most groundbreaking result we could have in quantum computing. Their evidence does not satisfy the burden of proof. They also only claim to have 1 qubit, which is intrinsically useless, and doesn't examine the costs of simulating multiple interacting qubits.