I do landscaping and property management in all types of weather. I get sweaty and dirty often, lifting, bending, crawling, etc. so my belts see a lot of activity. Additionally, how "rigid" someone needs their carry belt might be different per individual and related to what and how they are carrying. For me, once the belt shows a significant "bend" in the area I am carrying I switch... it might be related to the fact that my EDC has a shorter barrel, and therefore has more of a tendency to twist out on the top of the belt... or possibly my belly pudge. I don't know if the single clip for the holster also affects this.
I have a Hank's Gunner belt. It's thick and good quality. However, I wore it for years before I started carrying and it had started to soften and stretch by that time so I don't use it for carrying now. It's still a good quality belt, but after years of use and abuse it's too worn in for rigid support. Additionally, the thickness is an issue with some other things I like to put on my belt like my phone holster... especially in the area of belt overlap.
I used a Kore leather gun belt for almost three years before I noticed that it started to stretch in the area of carry (plastic core started to bend outwards in that area). I'm currently trying their nylon version and hope to get a few extra years out of it, as some report the nylon version holds up better... we'll see. If the Kore belt buckle is new to you, you might find that you get used to it quickly and soon it will seem easy to make those adjustments. You just need to move it 1/16" or so to lessen the strain on te racheting mechanism when you are trying to loosen it under heavy clothing.
I also occasionally use a Galco belt and an Emissary EDC Belt from Ciguera Gear Company. They have traditional belt loops so they're basically set and forget. If I were to choose just one for more active duties, I'd chose the Emissary. However, the Kore is the most convenient for me, as the adjustability makes it more convenient for different carry options, different activities, etc. It is my most worn belt. I also bought another leather version for when I'm not doing more labor intensive activities.
Although I know that some people say their belts last for years and years and years, it's my understanding that it's not uncommon to replace a good quailty CC leather belt every 3 years or so (if worn everyday). I guess it depends on how you expect the belt to behave, and how it works with your gear and activity. Once I notice a significant outward bend wear the holster sits, it means I print more, and I'll replace it. If you read through some of the reviews, even the metal cored belts will do this over time.