Normally new altcoins give more profits because the old altcoins have tons and tons of bag holders. These bag holders are usually going to sell at break even or near break even so there is more sell pressure.
It is only in theory. Nowadays, new altcoins only give more losses because most of them are easily dumped after they are listed in the first exchange. Meanwhile old coins may give good profits because we can buy them with cheap prices during the dump in the market recently. Then, we can sell them in the next altcoins season.
A new altcoin generally has everyone in profit and they are less likely to sell when there is a small move, hence its why they usually go 10x and more people end up making money. Go look at the CMC of 2017 and see how many of those mid type alts are dead right now and bag holders is the real reason.
Unfortunately, it is no longer the new altcoins in 2016, 2017, or 2018. In these years, I know that ICO was very popular and people can easily get enough profits from the new altcoins getting from ICOs. Nowadays, it is very difficult to get profits from new altcoins, moreover if the new altcoins have very low day volumes in the market. They probably will end up to be dead altcoins.