We can't really tell for now and Cardano price is still far below comparing to Ethereum. Cardano price $0.4224 and Ethereum is $3,514.29 so this comparison is abnormal because the gap is too much. Before Cardano reach $1, Ethereum might reach $10,000 so this comparison is not fair for Ethereum.
And I a simple way to the question, I will say cardano will never replace Ethereum even in 2 centuries. And I know because you like cardano token and that is why you are comparing these two.
I would guess that what they are talking about is market cap, and not the price of the currency because that would make more sense. Price wise ADA can't reach ETH at all, that would not be possible, and to be fair nobody really expects it to catch neither, but marketcap ranking is another discussion.
Not that it will catch there neither, ADA has 15 billion marketcap whereas ETH has about 420 billion (lol) so I do not think that we are going to see ADA pass there neither. So, only thing we can have right now is the question "which one will make you more money if you invest right now", and in that situation ADA has a chance, doesn't mean it can win, but at the very least there is a possibility of ADA being better investment.
Both in price and market capitalization are very different here, considering what ADA and ETH have achieved is very far, so I don't think it's comparable because ADA is far behind ETH, so the development of the project ADA looks more stagnant and there are not many updates or applications built on the ADA network, but ETH has tremendous adoption until today the issuance of the ETH Spot ETF, it's a step too far and seeing that the blue chip of the crypto currency market is Ethereum so I think ADA doesn't even have much opportunity to grow like ETH.
To see whether or not it's profitable probably depends on the market adoption where they will see projects built on both and where they can benefit, and I think ETH has much more potential than ADA even though the price is still cheap.