I've seen more riders since I started commuting about 5 years ago.
And New York City DOT confirms that there has been a big increase
in cyclists. It's not a coincidence that in this time period, NY has been
adding bike lanes all over the city.

" What have you seen and what will it take to get more people out there?"

Same thing that worked for the Netherlands, Denmark, Colombia, Oregon, etc.
Pretty much everywhere in the world; build bike lanes and the bikers multiply.