It's not a five year old product, it's not even 2 years old. They just aren't that powerful.
And don't tell people what to do, you come off bossy and rude.
What impact do you have?
Here's my Dewalt impacts so far.
DCF885 1/4 in driver, DCF883 3/8" impact, DCF880 1/2" impact, DCF891 1/2" mid-torque impact, and a DCF899 high torque impact.
The DCF883 3/8" and DCF880 1/2" are only rated around 125ftlbs & 150 ftlbs respectively, so they obviously aren't made for lugnuts, axle nuts, crank bolts, etc. If you bought one of these and were expecting more, shame on you for not looking at the specs for what you were buying. They are for under the hood and light suspension work (sway bars, shocks, etc) and for putting parts back together so you can finish with a torque wrench and they are perfect for that. I sure wouldn't want to put my larger impacts on oil or trans pan bolts, for example, but these are ideal for jobs like that.
The last two on the right, the DCF891 and the DCF899 both test right about 600 ft lbs and will zip off your lugnuts all day every day. That's what they are made to do. The DCF891 is newer to me and the DCF899 I've been using for more than 5 years now and I've not yet run into a lugnut it took more than 3 seconds to remove, not even on our GMC Topkicks.
And FWIW, Dewalt also now has two newer high torque impacts, the DCF900 (895 ft lbs) and the newest addition, the VTec DCF961 (>1,000 ft lbs), tested as most powerful 1/2" impact ever made yet to date, cordless or pneumatic. If I were to buy today I'd get one of these, but I've not ever ran into anything that's defeated my impacts so far to give reason to upgrade yet.