Which are the best competitors to Ethereum, and why do you think so?
(I know on top of my head that Cardano and IOTA try to challenge Ethereum,
although they still haven't proved much from my understanding?)
Not Neo or Eos, I don't agree with what you say. I am more able to accept if WAVES is called the toughest rival of ethereum, because in addition to having almost the same technology, WAVES is developing with a large volume. It's just that, ether is more popular and is more often used for ico wallets, even though both actually have smart contracts.