Have never taken any cue from wealth guidelines. In fact players know that items gained in our campaign are to be savoured. I do NOT ever check their wealth with the guidelines. Generally they are below the required, but after a big find may jump above...I am not sure I have never checked.
I agree with MerricB. Class, spells etc ALL impact on what monsters can be defeated. And let's remember not ALL monsters need be defeated. I rarely take any notice of CR either. PCs often fight creatures well below and sometimes those well above. Fleeing is always an option...

And one several players need to learn. I find it odd a group of players could go into so many life-threatening situations (and to me ANY fight where there are sword, axes, claws and magic is life-threatenting) and win every one...
Our current 6-7th level group has NO magic weapons. They just haven't come up much as treasure. Well they did have a cursespewing mace, but felt it was too evil, so they destroyed it. I loved that.
I don't use the guidelines for new characters either. On rare occasions I have given a PC the wealth a starting NPC would have - and they still come in better equipped than most active PCs. See, choosing the items makes for a far superior PC too. You can gear every item towards you primary focus. I am not in favour of that. But I treat NPCs the same way...
Here is a cut piece from the NPC creation doc I have done for Cellworld (our CS). I use these guidelines for PCs too. Yes, even at first level. So at 1st level a character may be ABOVE the recommended. But the item (if one is rolled at first) is random (although I generally make if of some use), and sometimes the player is even unaware of its powers. (I have started campaigns where a PC didn't even know they carried a magic item.
Here is the excert...oh and I forgot to mention...I love randomness
Gear
Magic Items
Roll a d10 a number of times equal to NPC’s level. The NPC gets a MI each time the dice is equal to or less than the number started at but the number drops by one for each roll (descending dice). Eg: for a 5th level NPC you need to roll a 5 or less, then a 4 or less, and so on down to 1. Hence 10th level and higher characters gain automatic MI’s and a chance for more. (NB: Halve all levels of Commoner, Expert and Warrior NPC class levels when using this mechanic).
Of course high-level characters may begin with many MI’s. Not all of them need be carried on them. You may even simply disregard some items. Don’t re-roll items that may not suit NPC – these items could be treasure gained from other defeated foes, but a NPC should have some items of use.
To determine the power of a MI roll on Table 10-1 below:
Modifiers:NPC under 5th level -1
NPC above 10th level +1
Table10-1 NPC magical item power (Roll 1d10)
0-6 Minor
7-9 Medium
10+ Major
Special Items
Determine the number of special items exactly as MI’s above. (Remember if the NPC has a HL feat it automatically starts with bonus gear).
This includes masterwork weapons, armor and kits, poison, alchemical items, special substances, spell catalysts, etc
Mundane Equipment
To finish, give the NPC a set of clothes and any normal items that an NPC of this sort would have. Starting kits detailed under classes and as a web enhancement are good ideas for low-level NPCs.