Given the average risk/reward and probability of winning trade is the same, short term trading will be more profitable. Bear in mind intraday trading can be scalping say 200 trades per day to maybe 2-3 trades per day depends on your style. Also need to factor in commissions as they play a larger role with smaller profit targets and stops. Inevitably one needs to do longer term trades as the account size grows because of liquidity needs.
When I day trade, I use no stops, even if I put stops of 10.00 points away in ES, if fat finger trader would hit 100,000 contracts-his orders are in the market already and I'd end up going way beyond 10.00 points, I know this, I might be the only day trader but I doubt it, I do Call or/and Put Debit spread options in SPYs as they more liquid than ES, they are done at very beginning of my day and one side or part of is liquidated 75 minutes later as I am done day trading manually, whatever is kept is monitored during the day to recover losses/make profits, I have a slight bias based on daily charts and overnight. I use them as Catastrophic insurance and only have 50% commitment to overall number of contracts traded. It does take away from bottom line, but gives me some risk protection. I don't have any idea any more of risk to reward, I don't base percentages that way in day trading, I test signals every couple of weeks to find optimum targets and areas where trade is likely to be wrong and not recover. I actually can't stand probability of profitable, non profitable trades, we all go into long debates of 50/50 or how money management can alter. I trade not to lose.
I was very very lucky not to have a computer first eight trading years, you had to think in terms of long term, commissions were over $100 bucks for one side in stocks and $150 to do futures of half side. Gave me many years to study but not refine my mental under-development issues and getting computer........wish I never got it, I did well in stocks, I was lazy using computer, I lost and lost, and lost etc, being fast is not being smart, uneducated trader is Bait, period. I love computers now cause of automation.
Long hours of just study, take any chart bar by bar and give each bar a label, a description of what it is, do that for 200 charts, then you start understanding what makes sense and what doesn't, what can happen and what can't.
I trade grains a good deal long term and use stops, most will place stops before day session opens, I never do that, I wait till open and after ten minutes, place my protective stops, and why most might ask why? I have found in my youth that too often market would jump over my stop getting me out at worst possible price of the day and very often market be up on the day and I was out of the market throwing things. If after ten minutes, I place my stops a bit below current days' lows and monitor so I can get my stops to where they needed to be. As simple as this sounds, took me a dozen years to come up with this. Many little nuances in trading you never read in books. And back testing is Hindsight to give us a chance of positive expectations.