It’s a poor design vs other systems that don’t have to rely on a pump if they fail. Even lifereef over flows don’t need a pump.
Oh, I get what you are saying now. The pump isn't required its just nice to have. It will keep siphon without it, but I'd rather be safe than sorry, any HOB overflow can lose siphon and I'd rather spend the extra $20 than have to pay for new floors