Ask HN: Why does software demand stay consistent when there is unlimited supply?

I understand essential goods like food are constrained by both demand and supply. But, why does software demand stay so consistent? For example, my addon [1] gets 40 - 50 installs per day like clockwork. When I was a newbie, I used to worry that everyone will install/uninstall my software on the same day during launch and I will run out of users sometime soon. I learnt it doesn't happen that way. But, I haven't figure out why. Why is that 40 - 50 people discover my software everyday consistently, when there is no supply constraint?

[1] https://gsuite.google.com/marketplace/app/formfacade/743872305260