Both altcoins are very popular, of course more people support Ethereum, but time will pass and perhaps Polkadot will be able to catch up with Ethereum or even overtake, just need more time and judging by how Polkadot develops, I think this can really happen, but it is hard to say which of these altcoins will increase in price the most in the coming days, perhaps Polkadot, because Polkadot has been growing very much in price lately and I think Ethereum will grow in price more when will be next news about Ethereum 2.0 development.