People need to stop talking about this as a binary yes or no fact. It is almost guaranteed that it is possible to infect someone else while not showing symptoms and this probably has actually happened. The question is how common it is. Most credible sources I've seen seem to say that it is unlikely/uncommon.
It seems likely that if we fully controlled most of the cases that had visible symptoms, the spread would stop, even if we failed to control the cases which did not show symptoms.
The same is true for spread via surfaces: while I'm sure it's possible and happens, it seems like the primary mechanism of infection is breathing infected respiratory droplets from someone else.
Last guidance I saw from the CDC was that people without obvious symptoms were likely to only be contact-infectious, as opposed to airborne-infectious (droplets) once symptomatic.
If true, social distancing, hand hygiene, and not touching ones face would bring asymptomatic transmission down to almost zero.
It seems likely that if we fully controlled most of the cases that had visible symptoms, the spread would stop, even if we failed to control the cases which did not show symptoms.
The same is true for spread via surfaces: while I'm sure it's possible and happens, it seems like the primary mechanism of infection is breathing infected respiratory droplets from someone else.
Sources: https://www.cdc.gov/coronavirus/2019-ncov/about/transmission...