Most likely, the term “alternative season” appeared after even with a good price growth of bitcoin, almost all altcoins were left without any significant growth. This has actually been going on for the last two years, so many began to talk about a possible increase in the price of altcoins, that is, about the "altcoin season" or "alternative season".
Well, sooner or later such a season should come. Altcoins are even more viable than aging bitcoins.