It would be an advantage to local companies - yes! At the moment, local companies are often at a disadvantage because they're paying more tax than those companies who are legally based overseas.
If the product or service doesn't exist locally, then the purchasing company will indeed need to pay tax, if and only if it's local sales are greater than local costs. If buying this overseas service such as AWS hosting gives it an advantage such as cheaper and simpler scaling then it may well be worth them buying it to pay the tax.
At the moment, an outside company can come in and pay little to no tax by licensing IP from another subsidiary in a third country. A local company is then at a disadvantage and is effectively paying for the infrastructure through their own taxes to support a competitor.