I’m based in NYC and frequently fly to KUL (mostly in J). I switched from Cathay to Qatar about a year ago, and already achieved Platinum / OW Emerald while the exact same flights would have just earned me Cathay Gold / OW Sapphire. Cathay was very generous in maintaining my Gold status throughout the pandemic but the J fare got so pricey to the point where QR was cheaper so between that and easier to attain/maintain status, I switched.

I’m by no means an expert but sharing my experience in case it helps:
- there’s a minimum requirement to fly QR, so if you are not planning to fly QR at all, this may not be for you
- AA flights credit with higher points than BA. No idea why but even when I fly BA, I purchase through AA
- When I was researching which OW alliance to switch to, multiple folks shared that Iberia was the easiest to attain status. I ultimately did not go this route because I have never flown Iberia and don’t frequent a city where Iberia goes to. I think it doesn’t matter but I personally wanted to align with a FF program that I would at least utilize the airline sometimes, since ultimately that’s where I would get the best treament
- The Al Mourjan North Garden Business Lounge and the Al Safwa First Lounge in Doha are two of the most impressive lounges I have ever used. I’m very happy to transit via Doha
- Q Suite is currently my fave J seat hands down. Prices seem to have increased since I started flying them though so realistically I may need to find another program if flying QR becomes unattainable

I would suggest you map out your flights and use the points calculate on both CX and QR to figure out what makes sense for you. There are also some posts on the One World board that might help with the decision. Good luck!

PS I just read that OP is trying to maintain Cathay Silver status. I found Silver not to be meaningful, I would find a way to be able to attain at least Gold / One World Sapphire which is when you start getting access to Business Lounges and checking in at the priority desk