This is a gimmick.

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That's all that really needs to be said, however the last time I said this my comment was auto-rejected for being too short, so now I am forced to elaborate why this is a gimmick.

1. The amount of harvested power is trivially small. Even if this was a busy walkway, constantly filled with people walking over it, best you could do is keep an LED light bulb lit.
2. You can't really scale this up. You're stealing mechanical energy from traffic and pushing it through an inefficient conversion process to electricity, then charging a battery with losses, etc. The energy is not free.
3. On a walking path you are making the path more difficult to walk on. On a bike path it's more difficult to bike on. On a road it's more difficult to drive on. Doing this for any long distance will be a terrible user experience and lead to a lot of wear and tear on both the harvesting device as well as the users/vehicles. You're better off putting a person on a bicycle generator, but that wouldn't be as gimmicky.
4. This is not fighting climate change. There is a non-trivial amount of energy and materials embedded in the whole system. Given the super-small amounts of energy harvested, you will likely forever be energy-negative with your investment. It will break down and be junked before it ever comes close to paying back its energy debt.
5. It's a gimmick.