For those with earlier model TJs, it looks like the cruise control (CC) buttons are a different design. I was also having the same issue where it seemed like I had to push really hard and leave it pressed for a few seconds or in a very specific spot. For reference, I have a '98.
Removal of the CC button housing from the steering wheel is very easy, a T20 torx screw can be accessed from the backside of the steering wheel. To make removal easier, you can remove the airbag secured by 2 hex screws (forgive me I'm forgetting the size but I think it was slightly larger than 3/8", like 7/16" or 13/32"). PLEASE DISCONNECT THE BATTERY IF YOU INTEND TO DO THIS. Once the torx screw is removed, don't try to pull the housing off axially (torwards you) as you'll break the tab securing the CC button housing to the steering wheel. Instead, you'll have to remove it by sliding the housing radially (torwards the center of the steering wheel). I think you can do this without touching the airbag but since it's two screws I usually opt for getting the airbag out of the way.
To take the pivoting button off, it's easier to get to the pivot point from the rear (those white tabs in the photo above). I just take a screwdriver to easier accessible one and then you can pop off the button. Be careful because there's also a rubber protector/boot and some small metal bridging plates that may fall out since the button is upside down.
Flip the CC button housing right side up and remove the rubber protector/boot. That will reveal the bridging plates which can also be popped out to reveal the contacts. The contact pads looked clean so for the older design switch, I think the issue is more about general wear and it being difficult to fully depress the bridging plate.
What I did was since there are three contact pads/bridging plates but only two button functions for the left steering wheel CC button, on/off & set, I took the bridging plate from the middle function that isn't used and added it to the backside of the rubber protector for the on/off function. Since all you're doing when pressing the CC button is pushing against the bridging plate, why not add a little extra material inbetween the button and the bridging plate to make it easier to deform. That's what I did for the on/off function and now that it's reassembled, all I have to do is a nice, easy press of the button and CC turns on without any fiddling.
As a departing tip for where to press on the button itself, the little nubs on the backside of the pivoting button (not photographed) that deform the bridging plates when pressed are right behind the "O" in "Off" and the "S" in "Set". If you're having trouble engaging either function, focus your pressure in those areas of the button.
