there really isn't any kind of limit to how much you can profit from investing in altcoins. it can be from losing 100% of your investment and going down to 0 up to millions of dollars!
it depends on a bunch of things. starting with your experience in trading and in knowing how altcoin market works conversely the pump and dumps. if you have no experience and want to randomly buy based on what others tell you and what they hype up then you will end up losing a lot of money.
then it also depends on how much you are willing to invest and take risks. obviously you can't become a millionaire investing $1 but you will be taking a much bigger risk investing a higher amount.
Yeah, a lot of factor matters and most of it depend on one's trading knowledge. One can make based on one's strategy or as much as one wants to, but it all depends on when the market simply looks like the possibility of a trend wants to change. However, in cases of bull run for altcoins, it can be very huge and can even start from as much as x10 and above for some alts. However, some still always get greedy and lose out anyway which is why greed is also an important thing in how much one makes or not.
for the benefit I get quite a lot through Altcoin. with the ability development Altcoin I try to trade with Altcoin I have and generate substantial profits. so it is great for the future to continue to support and run trading against Altcoin in the future and make it a major advantage.