I'm sure the POS at your corner store somehow interacts with AWS or GCP, but I'm not sure that should 'count.' As well as not visiting any site that is hosted on a cloud provider.
You could almost certainly live a life with significantly reduced quality by living without the tech giants directly, but to not visit websites that are hosted on AWS, and still shop at a local shop that uses Square or other payment provider that's hosted in the cloud seems disingenuous to me.