Ideally, you'd have a much better experience if you'd create a 'folder' (or many!) in Alpine (ie, a 'label' in gmail) and put all your old email in there. Still just as accessible, but out of the way. Alpine can be set up to automatically move read emails to a folder if you'd like. I don't use it that way though, as I move them into particular folders (in alpine) or delete them, as needed.
In the Alpine settings, you can set the initial folder view to be 'unseen first', which would put new emails at the top of the list. See 'Incoming Startup Rule' in config settings. You could also use the default sort settings to preset 'By Arrival, descending', which would put newer emails up top too. Still awfully cluttered with zillions of old emails there.
Be sure you're viewing your 'INBOX' and not 'All mail', as gmail actually stuffs everything into 'All Mail', and then, based on any labels on the message, 'emulates' a folder in the normal imap client. (Personally, I think google's "relabeling" of an existing protocol is absurd... ONLY google's gmail clients use the word 'label', whereas everything else says 'folder'. They're interchangeable when using gmail.)
Using appropriate folder names (uh, labels?), my email is sorted into various categories, while my inbox typically only has new emails and 'in-progress' issues... subsequently moved (or deleted!) when I'm done with them. This usage method converts well when used along with gmail app on android, and gmail web page.