You made good point, it doesn't matter the kind of coin you hold hence there is a bull run the price will rise.
However, what really needs to be noted is:
That not all altcoins are able to survive and ultimately rise in the bullish era. not all altcoins can be like that even in a bullish era. There are many altcoins that were bullish in the previous era but only stayed at that number and couldn't rise up like other altcoins. This is why you need to be very careful if you want to invest by holding altcoins. because again, not all altcoins can rise up in the bullish era. Meanwhile, if it is Bitcoin, it has a bigger reason to rise up. So, be careful in choosing coins for holding.