IOTA - should we invest?

If there are no fees in IOTA, what fundamental demand exists for the currency? What is preventing other blockchains like Ethereum from allowing people to move their coins to a side/pegged chain based on the DAG tangle? With the advent of inter-blockchain systems like Cosmos and Polkadot, you must consider the long term value of coins in a future where any cryptocurrency can exist on any blockchain. If people can move other coins to a free tangle-based chain, why would they buy IOTA?