Each altcoin has a different development schedule and several have recently entered the market with their respective communities.
Solid project have their own time frame in regards to it's developments and progress, you can't generalized the season to be the same.
It could be said that the altcoin session is not ending any time soon.
It did not, there are still progressive movements in terms of value, most of those top assets are still moving upwards and still providing
good benefits to all those supporters who hold their alts assets.
2021 is where many crypto newcomers decide to invest in altcoins considering the price of bitcoin is too high to pursue.
There are many new players who invested to this market, not just with bitcoin but also those known coins around.