It might be interesting for an external party to have such a website but it's counter productive for the government to have one because clicking a link on an on

It might be interesting for an external party to have such a website but it's counter productive for the government to have one because clicking a link on an online petition accomplishes literally nothing. How invested you are in an issue is displayed by how much work you're willing to put into doing something about it. Online petition is practically zero work so it's zero worth, regardless of how many people click what.