Yes, that's why about the only things the industry can do are denser basestations and higher frequencies.

Think about it as your home wifi, it's essentially the same, how do you increase its capacity?

If the industry doesn't have to factor in ROI, then your argument is valid, but it's a business.

Yeah, the laws of physics are not the limiting factor here. With faster compute, you can do better beamforming. There will always be lag between what is technically possible and what standards exist and are deployed, but I don't see any reason why wireless won't get faster over the coming years.

Channel capacity depends on signal power, noise power, and bandwidth. Bandwidth and signal power are bounded by government regulations, but if you can make your antenna more selective (rejecting more noise) you can transfer more bits per second over a channel. MIMO/beamforming is one way to do this, and it is mostly limited by DSP power. Compute/watt isn't really increasing exponentially anymore, but it is still getting better, so we can still squeeze more capacity out of available bandwidth.