He didn’t get a single cent from finding those coins. Items that old are considered government property and anyone who finds them is required by law to hand them in for free.
There was (is?) a requirement from Sony and Microsoft about how long a game can take to load as part of the game licensing process. One of the ways it is measured is by counting time from game boot to how quickly the game can react to user’s keypress. A “press start to continue” screen is the most simple thing you can load that passes this requirement. After that the game can do heavier operations such as loading save data, checking DLC or pulling latest messages from online server without having to worry too much about how long these operations take.