However at this £1k price point, GFN is significantly better than gaming laptops.
Again nope, you can get 5060 level machine for 1k that will play titles like fps or in my case racing games better native than GFN, certainly there were some benefits to GFN if the game doesn't need great latency like having more VRAM than any GPU on sale for gamers etc and access to a far more powerful GPU than you'd get in a laptop, it did amuse me that I had a 48Gb 5080 or something like that on the Ultimate tier and could set higher settings than my desktop. Great for slower pace 3rd person stuff like say Indiana Jones and things like that.
But on the normal performance tier a 5060 is better than its 3060 and whilst yes that does need mains for full performance, its battery performance is > 3060 level, blimey even the B390 iGPU of Panther Lake can offer a better gaming experience on battery, now it might not put in as high an FPS as GFN but the feel is better because it has less stutter and better latency, in fact Forza Horizon 6 shows a stutter count, it is in the 100s for GFN whereas the laptop same settings maybe 1 and that's using a reasonable latency wired connection to my fibre broadbrand, put it on random wifi or 5G, it gets even worse.
B390 on battery (not even a good one as laptop only has 7400 RAM.

would be faster with 9600 that some come with)
GFN Performance tier
A 5060 is twice the power of a B390.
So yeah if you want battery life and have no other option go for GFN but don't believe you are getting a better experience because it just isn't the case, you are a getting a good experience with caveats, I use it, I like it but I know what it is and isn't.
As you say though likely a moot point if you want a Mac.