It's impossible to fully prove a counterfactual, but few things "wouldn't exist at all" if "that one person" hadn't done it.
Netflix is a decent example. Many people saw the coming of video streaming. We would still be able to stream videos today even if Hastings had stayed at Rational.
There are also products that seemingly should exist but don't because no would-be inventor has found capital, eg. a decent bluetooth keyboard+trackpads with the same layout as a laptop. I know because I spent an hour trying to find one yesterday, and they basically just don't exist.