Why are dilution refrigerators becoming the bottleneck for quantum scaling?

[Steady Dylan]

Multiple news stories mention dilution refrigerators as limiting factor for quantum. These are just cooling right? Why is cooling the blocker not the qubits themselves?

[CMPunk_Fan]

Qubits need millikelvin temperatures to maintain coherence. Dilution refrigerators are only way to achieve and maintain those temperatures at scale. Design limits how many qubits you can cool