Unknowing if there is a similar study on virus occurrence in our daily life environment, but for pathogenic bacteriae, the highest count is noted on mobile phones .

The fingers/hands (touching the phone, amongst other things) are then by your fellow traveler , at least partly separated from bacteriae carried, and in turn spread out on all the surfaces you mention.

The scolding teawater poured over the towels before distributing, might be bactercidal, if people could stand holding a v-e-r-y hot and damp towel for a prolonged time of at least a couple of minutes. Personally, I tend to grab two corners of the towel and wait untill less scolding, as I see that service only to help me essentially cleaning my hands before meal service. This as I've touched diverse surfaces not clean, maybe read a newspaper, or whatever. It would be a tough situation if everybody queued up for the toilets, to wash their hands.

As for people declining the onboard towel service, it's a free world, and anyone using own wipes, or content with eating with unclean hands is at the liberty of doing so. If the reason for declining, however, is fear for being infected with coronavirus, it only shows that superstition beats science in the eye of the public, hands down, every day.

Just waiting to see a Youtube video on 'aircraft hot towels going viral'