altcoins can give you better gains because you can buy a lot of it and they have more room to grow in my opinion. An altcoin that have 1b marketcap and bitcoin that got 120b marketcap.

Let's compare

When an altcoin wit 1b marketcap grow into 10b marketcap, that is a 10x gains bro.

Compare when bitcoin with 120b marketcap grow into 150b marketcap, will only give you 20% gains.

i hope i helped you. But remember to choose altcoin wisely. Choose an altcoin with  lesser supply, or even not less supply but got sound project that you think is vital and really really will be there and prosper down the road in the next few years.
for ex: vechain. which is the most adopted supply chain right now. got huge partnerships and have good relationship with china. even though it got big supply, it is a vital company in my own opinion.