Ethereum is classed as a 'coins' on coinmarketcap -->
https://coinmarketcap.com/coins/Tether is classed as a 'tokens' on coinmarketcap -->
https://coinmarketcap.com/tokens/Comparing 'coins' with 'tokens' is like comparing apples with oranges.
Both 'coins' and 'tokens' have their own marketcap and ranking on coinmarketcap. I think investors / mainstream world will understand the difference between the two.
Also remember that tokens running on one single coin's blockchain will have a single point of failure (which is the network, over which they don't have any direct control).
You can see that happening with Ethereum right now that has network congestion, high gas fees, even higher fees for interacting with DeFi protocols and network security that is getting threatened.
All tokens projects operating on the Ethereum blockchain will be negatively impacted equally by all that.
From a decentralization point of view, having so many tokens projects operating on one single blockchain that can not scale, is a terrible concept.
Exactly. Both Ethereum and Tether are different from one another. But if Tether goes above Ethereum in terms of market cap, you'll expect most of the attention to go towards USDT. The average person does not care if cryptocurrencies are different from the other, as market cap is taken into consideration. If Tether becomes the second crypto asset besides Bitcoin, people might invest heavily into it. While prices will remain the same ($1 USD per coin), Tether will become the biggest stablecoin in the world. One interesting fact is that Tether lives on multiple blockchain networks. Its rise will not only benefit Ethereum but also Tron, Bitcoin Cash, Bitcoin (via Omni), Algorand, and Solana too. Since people are required to own one of the aforementioned cryptocurrencies to be able to transact with USDT, it's a win-win situation for the entire crypto/Blockchain space.
With Ethereum's current high fees and slow transaction confirmation times, I doubt people will continue to use USDT on the ETH blockchain. Tether will gain prominence on other scalable blockchain networks like Tron and Algorand in order to boost adoption of stablecoins in the mainstream world. Of course, we cannot deny that Tether has some shady practices. It's constantly "printing" new USDT tokens across multiple blockchains, resulting in a higher market cap. If it goes down the drain, it might take other cryptocurrencies down with it. That's largely because the market is extremely dependent on stablecoins to succeed. And since Tether is the largest stablecoin in the world, it can either positively or negatively affect the entire crypto market in a blink of an eye. At least, we have many other stablecoin alternatives to choose from. Other centralized stablecoins like USD Coin and Binance USD seem to be gaining prominence in the mainstream world. They might take Tether's place in the future if it goes down the drain. Surpassing ETH or not, it wouldn't make much of a difference since stablecoins are just a "glorified" version of Fiat. Technically speaking, cryptocurrencies and stablecoins are completely different from each other. Just my opinion