What happens if I “unclaim” fund from Optimistic Eth L2 over to Mainnet?

From Optimism Gateway, after hitting withdrawing button and roughly a week later my funds in L2 to is ready to claim. However due to high gas fee in relation to small amount that I would want to claim, I decided not to claim. which sucks.. So, what happens if it is unclaimed? With some time if it is unclaimed, will it go back to L2 automatically? or will it unclaimed forever if I don't claim it?

Another question, What's the point of having a week of holding fund if it still charges high gas fee? Isn't it pointless to even have the option between using Optimism or Hop?