The stuff that follwed was more of a hard fact than this part.
No it isn't. We're in a bear market and "investing" in altcoins can make your capital shrink. It's as hard fact as it isn't.
I believe it all depends on "alt" we are talking about. The problem with the word altcoin is that it consists of everything from ethereum and bnb to all the smaller ones that are not even in the top 1000 of CMC right now and even ones that are not even listed there. So, that means when we are talking about alts, we are talking about a vast one and I agree that majority of them would shrink it, but the ones like ETH would probably not cause that.
This is why I personally try to make sure that we do not invest into silly stuff that could be a scam, but we would definitely invest into high level top 5 ones that could go on to be major players like bitcoin in our future.