Well both are profitable but it depends on your capital, if your capital investments is high then you will get more profit in day trading and the best thing about long term investment is if your capital is low still you get some good profit amount.
And it depends also in what coin you're holding if its for long term or just a day trading.
There are coins that are more profitable in long term like just watch the market and let it sleep in your wallet and go back after some years. And some are day trading like you need to closely track and the coin is hype or active in the market.
Choose wisely a popular coin for your long term holding and a new promising coin for the short term.
I do both by the way , for balancing my income, current and future profit should be planned.
If you are a day trader then nothing wrong in even investing in shitcoins as if the price pumps then you can make huge profits but there is also an risk of loosing money and every time decision won't go in your favor so its better to invest in top 10 atlcoins and hold it for a long term to make good profits from it.