There are pros and cons (like with everything), e.g. if you fly from/to AMS/CDG you can get a direct flight and still get lounge and XP (if you buy the AF/KL coded flight - which might come more expensive than the BT of course). Also, you might be lucky to get the Starlink equipped 220s of BT with free internet

on the other hand, if you are traveling from/to further than AMS/CDG and you can get a SK connection might be also good: 1) SK usually has good pricing (at least better than AF/KL), 2) you still get same XPs (no UXPs though), 3) free seat selection. Lounge access on SK should be better since Oct 1st (before that there was no benefit e.g. at VNO).