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.
All altcoins are not profitable but some of them can be and ethereum is a better example of this fact. Ethereum got higher value with the passage of time and as bitcoin is increasing and gets the curiosity of individuals so same is fact about ethereum that it is the largest and most important coin among all altcoins.
Beside etheruem there are also some other altcoins like Doge coin which previously showed reduction but now again upswing is showing by doge. Better way to take benefit during halving with minimum risk is to not hold every low price coin but choose just two coins like Bitcoin and etheruem in which your chances of lossing will be least.
i think there are just too many of us invested in doge as early as 2016 and some who have become millionaires are among those who made doge growth too slow. sort of a manipulation already and investors holding just a few doge are already impatient about this.
but just about any altcoins to hold today til the next few months after halving will still profit. some altcoins may not grow exponentially but they will still be profitable for an individual who will invest today. ETH is the primary choice for altcoin so that's an obvious option but even ETH price is also high. the ones that can be affordable are the ones that should be preferred.