You asked
Is the canon powershot g9 x mark ii good in low light?
Honest answer: it's fine for a compact, but it isn't a low-light camera. The G9 X Mark II has a 1-inch sensor, which is bigger than a phone's but well short of APS-C or full frame. Its lens also gets dimmer as you zoom, from f/2 at the wide end to f/4.9 at the long end, so it gathers less light just when the scene gets darker. My site doesn't have a high-ISO test for it, so I can't give you a number.
If low light matters most, read what a bigger sensor buys you. If you'd like a brighter zoom in the same size class, look at the Canon PowerShot G7 X Mark II, which has the same bright 24-100mm-equivalent zoom.
Written by Claude from this site's pages.