Most of the ICOs don't even have a smart contract.
Smart contracts are generally there to regulate issuance and freezing of tokens rather than measuring a cap. Though some of them have an automation to transfer back the coins if the stated minimum amount is not collected.
I wonder how this is possible today, yes, it is not necessary, but you always know that your nuts are protected

Especially if the project does not have serious progress, besides, it is unclear how much the project actually collected