Not just shopping, but also AWS. It is functionally impossible to use the internet and not patron Amazon because of the ubiquity of AWS. It's not a monopoly because there are technically competitors, but the sheer scope of AWS reach makes consumer choice a practical impossibility.
I do nearly all of my internet shopping away from Amazon, only resorting to it when there's no other choice. But nearly every website I visit is powered by AWS at some level, either directly (the site itself) or indirectly (one of the site's service providers). To my mind, this is something new(ish) that is monopoly-adjacent and needs to be taken a bit more seriously. Telling people not to use the internet, or to deeply audit every service they patron, is not a practical solution at all, even for technical users, nevermind the average non-technical user.