biggest number factored by a quantum computer isn't the right question. the right question is biggest number factored using a polynomial time algorithm. the answer to that as far as I know of still 15 (although I would be interested in papers that show more progress)
This is one of the things I really resent about QC as a field - there's so much chaff where one paper will say "we can do x" and the reality is that x does not mean what everyone thought that they meant. Number of Qbits is another thing - also what gates are implemented in the devices; how long they can run for etc etc etc.
Application of Shor's algorithm is currently limited by available error correction. Long-lived qubits would eliminate that need and drastically increase capabilities.
I'm not sure that you are correct. I've tried to read https://arxiv.org/abs/2306.10072 in the last day and if my reading is right (I am very stretched by this stuff so I am very happy to be corrected) then no amount of error correction will rescue Shor's - only zero error phase gates. I suspect that a similar story is true for native QML, as quantum memory scales it's just going to get exponentially harder to maintain it.
That’s what I’m saying, effectively zero error phase gates are on the horizon. My company is working on the tech that would make them possible, for example, and we have competitors working on other paths to the same thing.