I prefer to combine these two ways of investing. But short-term investment brings me more profit. But some coins will do better in the long run.
On my behalf, long term investing brings more profit to me. Because of being patient and not selling my bitcoin few years ago, I was able to join the craze and sold a good amount of bitcoin and made well last all time high. It isn't that much as you're expecting but I call it a better profit than the short term investing that I had before.
There are coins good for short term but you shouldn't ignore longing on the best coins.