Here are my $0.02. I’m not a professional or anything, so take it for what it is.
I don’t see alt season kicking off in earnest until bitcoin is starting to close in on it’s ATH. FOMO will be setting in and smart money take the opportunity to take profit and move part of their position into alts while still getting top pay for their BTC.
The market reacts a little slow. Once the smart money have finished the reallocation, bitcoin pulls back and alt season takes off.
This doesn’t mean you can’t make great gains trading alts in the meantime. I just suspect it’s a little early to buy alts for HODL. I’m sure they will take off at some time. I’m pretty sure they will go up as well. I just think bitcoin will be a better bet until it starts closing in on its ATH. Unless you get lucky and pick the alt hitting a pump at the perfect time. Or you are active in managing your portfolio...