I don't agree with you. First, ICOs and IEOs are still based on Ethereum platform more than others. Second, these days people are less interested in altcoins. So, less interest in Ethereum is normal.
Also I want to draw your attention to bitcoin. Bitcoin is now the oldest cryptocurrency. Many new cryptocurrencies have been created and had claimed to be better than bitcoin. But none of them were successful. I expect Ethereum to remain the biggest altcoin as it is the oldest altcoin. Not only oldness is not a disadvantage, it's an advantage.
That's certainly true, mate. However, I believe that Ethereum's dominance of ICOs and IEOs might come to an end as Binance Chain becomes a true contender of the same. It has already launched its own DEX, along with a token standard (BEP5) for the launch of ICOs and IEOs. Not to mention, Binance's smart contract platform will feature greater scalability and unparalleled performance than Ethereum. With various competitors around the market using superior tech and features than Ethereum, it might soon become outdated if developers do don't something about it.
The much awaited PoS consensus upgrade is taking too long into becoming implemented within the Ethereum blockchain. This will make people look for other alternatives which are more efficient than the pioneer smart contract platform. As businesses and corporations demand high performance for Blockchain operations, they'll look for more viable alternatives that provide faster and cheaper transactions than Ethereum itself.
As for being the one of the oldest coins in existence, it truly does have an advantage among other cryptocurrencies in the market. But sometimes it's necessary to move onto greater things, since other competitors are hungry of taking ETH's spot as the world's second largest cryptocurrency in market cap. By adopting Sharding, and Casper PoS in the least time possible, it can become comparable to other competitors which already make use of scalable technologies within the Blockchain space.
Nonetheless, Ethereum's success will largely depend on its level of development and mainstream adoption. It may still be the leader of ICOs and dApps, but that could change soon if other competitors take the lead in this regard. Which is why, it's important for the Ethereum team to bring innovation to the platform ASAP before it's too late. Just my thoughts