What's your opinion on buying alts during bear market and buying BTC/ETC stack during bull market?

BTC/ETH portfolio seems to be the most common, it has lower volatility compared to coins outside of top 2 and is considered lower risk while still providing great gains during bull market.

Idea behind investing to alts during bear market is that they tend to be much cheaper than BTC/ETC with much higher potential (and of course much higher risk) if we compare it to their ATHs and it looks like this cycle is a different as solid projects just refuse to die (for example SOL, ADA, DOT, MATIC and others in top 20).

To me it seems that some of those projects have successfully passed "test of time" and they survived the worst. They are cheaper than BTC/ETC, looks like they won't die and they may reach higher during next bull run. Once they sky rocket, they can be switched for BTC/ETC stack.

Of course there is much higher risk they won't perform as well as BTC/ETC but you know, you shouldn't put all eggs into a single basket.