Ionic 5 capacitor : Load the data of a page only once even if the page is loaded 1000 times

This is a cousin of a very typical question here, which is addressed here, and my fundamental suggestion is the same: don’t use lifecycle events to manage data freshness. In your case, once you get all the data wrangling out of the page and into a service where it belongs, the service can simply fetch data only on request, and it won’t matter how many times the page asks the service: the answer will be unchanged until somebody asks the service to update it.