Comparing a main stream touring act who does concerts in large pavillions or arenas for 10,000+ in attendance to a mobile DJ who does events for 300 or less, and often 50 to 125 guests is irrelevant.
Also, While Subs are probably used for concerts (I am no sound guru with a high level of knowledge on the standards on this) ...I have often not seen any subs in plain sight when I attended a large concert. What I saw were large array systems suspended in air. I could not make out any subs being used in plain sight.
Going back afew years to the old DJ Expo days where the Promo Only Concert series was taking place at the House of Blues...The sound was output through a large array speaker system to maybe 400 to 500 DJs in the crowd, and it sounded abolutely terrible, and overbearing, LOL. I figured sound quality would be horrible at a DJ Expo, LOL.
I was in a total dive bar in Odenton, Maryland (The Place, was actually the name of it) this past weekend listening to a band play that was using two subs. And there couldn't have been more than 25 people in there. The band sounded great, and it was a shame they didn't have a bigger audience.
If you're watching line array rigs being flown, there are definitely subs on those systems. Sometimes the subs are being flown, sometimes they're essentially built into the stage. But I think it would be hard to find a real line array system that doesn't have subs in it somewhere.
This has totally de-railed this thread, which I apologize for.
At the end of the day... you're going to keep doing what you are comfortable doing. I think they make a difference, so I use them. And the clients I want... are the kind of clients that care if I take an extra step to make sure its done properly.