Surface Book 2 13" has no fan on the CPU. The GPU has one, and the larger 15" has a CPU fan as well, but the 13" is dead silent otherwise. Although the charger can exhibit some coil whine at times which is annoying.

There's no point to aim on fanless laptop. There are plenty of laptops which won't turn on fan unless absolutely necessary, you should aim for those laptops, because if you need that extra performance, you'll have it and if you don't need it, you will have silent device.

The current Air might as well be fanless. The fan is nowhere near the heatsink on the CPU, once it finally kicks in it only pushes the air through the case, its impact on the CPU temperatures is minimal.

"It has a fan, but the fan is useless" is worse than merely having a useful fan :/.

Also worse than no fan, since you could fill that space with battery if there wasn't a fan there.

Yep. The only saving grace is that it takes a loong time for the fan to finally kick in, it's pretty much impossible to make it run with anything less than 100% CPU load, and even then it takes a few minutes to kick in.

Yes, but nothing without compromises. (e.g. AFAIK there doesn't exist a <2lb, >= 12" screen device with an Amber Lake CPU)