More power, extra lift, bigger tyres and diff locks can obviously all be helpful when it comes to off-road prowess. (But even here "user-controlled diff locks" are probably the only item to which it is very hard to associate any significant negative effects.)
What's overlooked is that "lift and good-suspension-travel" often equals "rollover" (on side-cambers). And extra weight makes a vehicle more reluctant to climb (out of a mire or up a slippery slope) and less likely to follow the changes of direction to which you steer it.
So what I'm saying is .... Most modified vehicles I see have a mixture of modifications .... some of them are beneficial and some are harmful (and which category they fall into depends a lot on the type of terrain they're travelling over at the time). But the overall result of all their "improvements" is often questionable in my eyes (with vehicle-reliability often seriously suffering).
The biggest factors on why they may go further than me ... are usually "the bigger size of their wallet" (whereas I can't afford to pay for repairs) and the fact they consider their vehicle easily replaceable (whereas I want mine to be still in top condition for my kids to enjoy when I'm gone).
The stock 40-series is a good allrounder I reckon and can in certain circumstances perform better than the modified macho versions (depending on terrain again).
And another BIG factor for me ...The stock 40-series is also very obedient/comfortable on-road (and I very much like driving mine on-road too).
But we digress........ Now what the hell was the original topic
One of the biggest problems these days is muppets with really big tyres. They make really big ruts which make these trails impassible for standard vehicles. Back when everyone ran what the vehicle came with the ruts remained shallow as the ground between them was graded flat by the diffs being dragged over them.
. Now what the hell was the original topic