Infrastructure, not qubits, is emerging as the main constraint on quantum computing’s path to real-world use. The view came from a recent Economist Impact roundtable, where quantum executives and researchers pointed to uptime, networking, and links to classical compute as the next barriers.

Panelists from Q-CTRL, Phasecraft, and the U.K. National Quantum Computing Center said the focus is shifting beyond qubit counts toward a broader stack spanning control, calibration, and software.

That reflects a wider change in the market as quantum vendors and users move beyond hardware milestones to focus more on whether systems can operate reliably enough to support meaningful workloads.

Michael Biercuk, founder and CEO of Q-CTRL, argued that “the non-quantum things are the actual bottleneck right now.”

“We are stymied much, much more by things like system downtime or poor network connectivity and infrastructure than we are by the physical qubits themselves,” Biercuk said. He contrasted providers whose systems are available “99.9%” of the time with others whose machines are down so often that users effectively rely on a “human API” to run jobs.

That kind of friction matters because quantum utility increasingly depends on machines functioning as part of broader computational workflows rather than as isolated research systems. Biercuk described Q-CTRL’s role as the “last mile” between algorithms and hardware, focused on virtualization and performance management that make quantum machines more practical to use.

Others on the panel agreed that the bottleneck is broadening beyond raw hardware, even if they were less categorical.

Ashley Montanaro, co-founder and CEO of Phasecraft, said control, calibration, connectivity, and integration with classical compute are all becoming more important as hardware platforms scale. But he cautioned against suggesting the hardware challenge is already solved.

“It’s not just about the number of qubits, it’s about what you can do with those qubits,” Montanaro said, adding that high-fidelity qubits remain essential if the industry is to reach fault tolerance and commercially meaningful applications.

Elham Kashefi, chief scientist at the U.K. National Quantum Computing Center, framed the issue as an ecosystem challenge. She said quantum utility depends on coordinated progress across algorithms, benchmarking, integration tools, and end-user workflows, not just on advances at the hardware layer.

That broader workflow view also came through in the panel’s discussion of use cases. Speakers pointed to optimization, materials modeling, chemistry, and energy networks as areas where hybrid quantum-classical approaches are beginning to show promise, even if large-scale commercial return remains limited.

The U.K. government’s recent $2.6 billion shift from funding quantum research to acting as an “anchor customer” for quantum technologies also came up during the discussion. The panelists framed it mainly as a way to support the wider software, talent, and user ecosystem around quantum, rather than as a hardware story alone.