Verification is important for several reasons. First of all, it is to avoid further complications during deposits and withdrawals. Secondly, the verification process is necessary to check whether the info you entered during the registration process is true or not. For instance, some underage players may want to gamble and fake their age on the registration form but their account will not be verified without proof that they really are over 18 years old so, they will not be able to deposit or withdraw.