Please explain BETH/ETH2 to me

How is it possible that ETH2 (kraken) and BETH (binance) are a lot cheaper than ETH?

Doesn't that basically mean that i can buy ETH with a discount as long as i hold it until the network goes live?
Why is anybody converting ETH to ETH2 if you can just buy BETH with Fiat on Binance?

I just don't understand the mechanism and motivation here.