PWA Apps are installed not from Google Play nor AppStore, that might distrust the customers
This argument is partially valid when the user receives the application by SMS from an unknown source. The workaround this would be registering the name of your company with cellular operators, which means that text message would not be received from the unknown number but from your company instead.
You can also personalize the text message by adding the first name of the person the text message is addressed to.
In addition, the mobsted platform allows you to work with the native as a container. In any case, installing an application from authorized sites is a standard and a guarantee for many customers.