Pros: You save money & reduce jaywalking. Cons: you spread germs and further erode trust and respect for government. The saved money and jaywalking compliance are Pyrrhic victories as citizens sass officers and vote for tax-cutting politicians.
Really? I don't think there would be any change or effect regarding microbes passed around the population if pedestrian crossing buttons did not exist. They just aren't a disease vector, or at the most optimistic are down in the statistical noise at a one in millions chance of having an effect.