It all depends on your world of course, but I'd like to play a game that took a different approach. Why not have the gear provide nothing but utility and no stats by default? I.e. wearing regular clothing doesn't help reduce damage, leather armor reduces it a little, chain more so and plate even more. They don't in and of themselves make your character stronger or have more HP (which is still a bit of a WTF moment for me, how does the gear make you tougher in a way that's not represented by it's defensive qualities?). You'd have to balance the defensive qualities with something else though, or plate becomes the obvious choice for everyone, including mages and thieves. I would argue that having all gear provide the same armor level would be a bit much for me to accept as a player without heavy justification.
Some games have taken such approach, I think Mortal Online is one of them. There gear only have your logical defense stats and it also slows you down and affects your mana to avoid rogues and mages running around inplate by default (although there, it instead created opposite effect, naked mages and thieves.. the irony). I was considering a system which devided gear into several tiers of defense, from very light (rugs/ light robe/ assassins gear) to heavy (plate armor etc). With such system, player would select appropriate tier for their play style, however there is still issue of preventing people to go naked.
One could argue that if there is social only armor in such system, free of negative or positive effects mages and rogues would chose to wear it instead of being naked, which is a valid argument I guess.
You might introduce quality levels and wear levels to differentiate a bit and give crafters something to do. Crude, low quality, average, high quality, master work, etc for quality, affecting weight and armor perhaps. Then you could have rusted gear, damaged gear, unmaintained gear, etc with similar effects. Allow players to upgrade the quality level and repair any wear.
Any stats that were provided by the gear would come from enchantments (which is presumably why a piece of gear would give +10 strength in the first place, unless it's powered armor or something). So you could enchant a chain bikini to give +10 strength or you could enchant a steel cuirass to give +10 strength, the underlying gear wouldn't matter. Allow players to add, remove or swap enchantments, and they the can do whatever they want with their gear.
Enchants is something I have considered, but I am not sure it is a good choice due to confusion reasons mentioned above.
The issue then becomes how do you encourage players to go to new places and get the gear there? By providing new looking stuff those that are interested in that sort of thing will go get it. You could also provide new types of enchantment, but you'd have to be careful about mudflation here too. You could possibly focus on things other than gear progression. That doesn't really exist in real life for example. There's really only quality and wear in real life (rolling things like construction technique and materials into the quality level). I've always viewed individual character development much more highly than gear progression. Give players things to chase other than the goal of having 10K armor or 100K HP. Real people generally fought and risked their lives for something other than the sword of dragonslaying, such as fame, wealth, duty, or a higher purpose.
That's a whole new ballgame of course, and every player wants different things, and you can't possibly hope to provide everything.
The bold part is probably the main question of this topic. How to encourage people to develop their characters for other reasons then new gear? If a game is PvE focused, players need rewards. Champions Online does have some minor rewards in terms of non visual items with stats, but that together with skill advancement is not enough imho. I am brainstorming implementations of some type of character bound enchants/runes/visual effects, but have not come long which is why I started this discussion ^^
What untraditinal ways to advance your character are there, besides talents, gear and player bound enchants?