Uncle8888 has been hearing it many times ...
Fight with one hand (Long only)
Fight with both hands! (Long and Short Traders)
How does it matters across market cycles of Bull and Bear?
Uncle8888 doesn't know what really matter?
But; he knows he has 10-year Target to meet and a job to do in the stock market.
Probably; he thinks the main difference may lie with the size of war chest and account. Long only retail investors will definitely require much larger account size and war chest than active long and short traders as long only retail investors will have to let both their cash and investment portfolio rotting heavily along their investing journey to earn those yearly dividends and some realized trading P/L.
Efficiency and turnover of capital may be very low for long only investors. Unproductive capital at work? ......