It depends on your investment, if you have lots of money for trade then obviously you should buy ETH. Because ETH leading the second position for almost 2 years. But you need to analyze more to find out for yourself.
The reason that you are saying is very common, because everyone also knows that ETH has been leading in second place for more than 2 years, so if because of this you c
hoose ETH for trading, it doesn't mean it's not good but the potential profit won't a lot unless you can afford to buy very large amounts when the price is cheap, because other tokens that have the potential are also good to trade as long as the market is still in a very good condition.
I would agree with you. ETH is very expensive now. Traders who prefer ETH should have bought it months earlier when it was All-Time-Low and hodl it to make a good profit. There are huge amount of volatile coins on cryptomarket now that are cheaper and can give you good grains on shorts (like Bitcoin cash and BNB).