Quantum Computers: A Brief Assessment of Progress in the Past Decade – Gil Kalai

From my research into QC, the main advances I see:

1. Breakthroughs in quantum error correction that is allowing IBM to promise a leap from 89 qubits today to 4,000 qubits in 2025 (still not enough on its own for a cryptographically relevant quantum computer - CRQC0, running Shor's algorithm for exponential speedup in breaking e.g. RSA 2048, which some research suggests would take 20M qubits including those for quantum error correction)

2. The breakthrough by University of Chicago researchers that showed multiple quantum computers can be entangled over tuned optical fibers to act as a single quantum computer. This still doesn't mean that we can go from 4,000 qubits to 20M by networking 5,000 of the quantum computers IBM promised for 2025, in 2025, but it provides a trajectory for networked quantum computing as a horizontal scaling strategy.