What world do you live in? Apps are either enshittified with updates, or the content source the app was using is broken in similar ways to a normal website.
The only way you avoid this are sideloaded non-networked apps - which are not the usual.
The useful executable code is contained on your device rather than fetched from a website. No update means you can run that useful code forever.
Not many apps are useful in that form though.
What world do you live in? Apps are either enshittified with updates, or the content source the app was using is broken in similar ways to a normal website.
The only way you avoid this are sideloaded non-networked apps - which are not the usual.