I have been telling my (online, because I don't know anyone in real life that even knows what bitcoin is) friends to get rid of their altcoins, because sooner or later there would be a massive bull run to bitcoin that would last months. They never believed in what I had to say. "Bitcoin maximalist" they would accuse me off.
Recently, they finally dumped their alts, which they were holding in hopes of a pump to make more bitcoin with, and simply held BTC. They have dodged the massive alt crash that has brought up BTC back above %50 of the crypto marketcap dominance.
Im not saying all altcoins are shit, but most are. It seems finally reality is kicking in amongst noobs that thought they could get easily rich with altcoins, and they are finally going back to BTC.
Your friends have definitely made the right decision at the right time.
However, this will not always be the case. Alts ar a lot more volatile than bitcoin is which means that there are a lot of opportunities and cases where alts will outpace bitcoin growth, especially after such a bearish season to start the month with.
Right now would be a perfect time to stock up with alts, in my opinion.