I agree with "unnecessary" but disagree with "stupid". Without the timer it can become a boring idle game if the dev isn't careful. might not be the right words... Without a timer people could sit on the gameplay screen for a long time and then get upset when they find out they hardly made any progress because they needed upgrades they could have afforded seconds into the gameplay session. I think having an indicator on the gameplay screen telling you have many upgrades the player can purchase could fix that issue. My preferred method is actually having upgrades available from the gameplay screen rather than having to restart each time you want to upgrade.
