TIL. Awesome. I still remain an arm-chair skeptic, but it's my guess is the reasons it's practical for storage (i.e. you need greater charge to make the tunnel, but the charge is durably stored because it can't tunnel out) don't make it practical for increasing transmission rate vs a direct connection.
Edit: Just to fix a confusion, by 'reliable' I meant, one electron sent, one received. I know one 'bit' isn't typically sent as one electron, but being reductive for comparison's sake. Obviously with enough current you can make the tunnel happen, but you'd need far more electrons and 'time' to do so.
Tunneling diodes are extremely reliable for signaling, which is why they've been used in early high frequency applications such as UHF TV and satellite communications they exhibit "FTL" tunneling just like any other case of electron tunneling.
The reason we don't often use tunneling diodes today in most devices is that they are expensive to make compared to many other modern diodes, they are still used in more unique applications including very sensitive scientific equipment and space applications.
In general there many types of semiconductors that employ a Quantum Well https://en.wikipedia.org/wiki/Quantum_well this means that these SCs do RELIABLY utilize quantum tunneling by either inducing it under very specific conditions, or averting it.
I'm really not sure what you are skeptical about, without use being able to utilize QT reliably we wouldn't be able to make modern semi-conductors they would either not work because we can't make tunneling happen when we need it too, or won't work because we randomly induce it to happen.
It doesn't mean we fully "understand" Quantum Tunneling as in understand exactly why it happens, but we know enough to predict and control it, Quantum Tunneling is to the SC industry what fire was to humanity in general for milenia. We still probably can only roughly model the physics of fire, especially since at the end it's governed by QM effects, but we don't need that in fact we don't even need to understand combustion that well to utilize it.
But if you want single electron tunneling then yes it's possible there have been papers about it for a few decades with the latest ones also including some experimental work https://arxiv.org/ftp/arxiv/papers/1204/1204.5539.pdf
I think it would be great if tunnelling could be exploited in this manner. I'm not sure what it means. Maybe FTL circuitry or other exotic mechanism are part of our near future?
Edit: Just to fix a confusion, by 'reliable' I meant, one electron sent, one received. I know one 'bit' isn't typically sent as one electron, but being reductive for comparison's sake. Obviously with enough current you can make the tunnel happen, but you'd need far more electrons and 'time' to do so.