There are quite a few options besides CMOS all with desirable properties and some of those with potential feature sizes smaller than Silicon. The problem is that none of these are economical at scale and that is where the problem lies, it's an economical issue, not so much a technical issue.

Bismuth, Gallium-Arsenide and other variations on that theme, various superconductors used for processing elements all have the potential or have already surpassed Silicon for various parameters. But none have done so in a way that would allow massive adoption.

So for now the 'economical inertia' as you put it so eloquently seems to be exactly where the problem is, inertia is only useful to get you past a hump when you're still moving forward, when you're already stuck it is a hindrance.