We saw what Ethereum outperforming Bitcoin in just a few days does to the market.
(over $100b mc was added to the market and that doesn't even include Bitcoin and Ethereum)
While I don't think $ETH /$BTC will make new highs anytime soon.
Imagine what the market will do if even a further partial retrace happens.
If we see a larger leg-up (see chart below), it would be the closest thing to what people generally refer to as a "traditional altseason".