Right, don't add complexity until you have to.

I'd argue that adding complexity from the get-go to ensure that all users have a pleasant experience from the get-go is better than simplicity at the expense of some percentage of users.

I think it's important for web devs to spend more than two seconds to think if the complexity is necessary from the get-go though.

When building out a new app or site, which means a percentage of zero users is zero.