Tl;dr: "This suggests, according to Briand, that the COVID-19 death toll is misleading. Briand believes that deaths due to heart diseases, respiratory diseases, influenza and pneumonia may instead be recategorized as being due to COVID-19."
There's little reason for a company owners to dilute their holdings with an S-1, if they are already profitable and don't have huge investments planned ahead.
As long as the table is bolted to the floor, you're replacing posession (of a phone) factor, with location (in SOC) factor. Keeps both client happy, and security architect sleeping soundly.
I'd hazard saying that the purpose of a YubiKey is to provide two factor authentication. A YubiKey acts as an item, posession of which implies identity. When you allow for the YubiKey to be activated without human interaction, it's moved from domain of posession into the domain of knowledge - identifying party needs to know where to knock, not to possess they key. It's no better than appending the URL at the end of your password.
If you allow for a YubiKey, or any other physical artifact in that matter, to be remotely invoked it negates its utility as an authentication factor in the physical domain.
Avoiding cloud works well for small requirements too - worked for a company that ran a global store; we've opted for dedicated servers on OVH, all together had about 40 of them. It was 1/10th the price of running the infrastructure on AWS. We still used S3 though.