Google Pay for Android takes up around 45mb (about 10 photos worth) - or about 0.06% of the capacity of my clunky 4 year old phone. If you change phones, simply add the app and sign on with your new one (most phone ugrades now allow very simple transfer of literally everything on your old device to the new one) - don’t understand what you mean by ‘no consideration given to this’ as none is needed. The tickets attach to your email address, not your phone number.
on the basis of your reply alone no everyone changes to same brand or operating system on phones