What do you mean? The original 2019 supremacy experiment was eventually simulated, as better classical methods were found, but the followups are still holding strong (for example [4] and [5]). There was recently a series of blog posts by Dominik Hangleiter summarizing the situation: [1][2][3].

[1]: https://quantumfrontiers.com/2026/01/06/has-quantum-advantag...

[2]: https://quantumfrontiers.com/2026/01/25/has-quantum-advantag...

[3]: https://quantumfrontiers.com/2026/02/28/what-is-next-in-quan...

[4]: https://arxiv.org/abs/2303.04792

[5]: https://arxiv.org/abs/2406.02501