Granite and marble have been in use for many decades (or centuries in the case of ancient architecture and sculpture), particularly in Europe. They’ve already stood the test of time, IMHO. Some of the more distinct or colorful patterns will probably look dated, but understated colors like white and black or grey will look just fine in 20 years especially if you go with a simple edge treatment (I.e. eased). Natural stones hold up well because they’re a natural material. What will go out of style are man-made materials like Quartz because technology will advance as it always does and newer and better things will come along, just ask people with Corian from the mid-90’s. But for a stone mined out of the ground that’s been sitting around for millennia, well that’s hard to improve on.
There’s a lot of misperceptions about granite maintenance. True granites require zero maintenance, no sealing, etc. But not everything marked as granite is a true granite. Stoneyards will give you a sample to take home and play with. You should absolutely do this if you decide on granite. Take your sample and apply soy sauce, lemon juice, vinegar, and tomato sauce and let sit overnight. Wash off in the morning and examine under bright light for etching and staining. If you see any evidence of such, don’t get that particular granite. Darker granites like absolute black and uba tuba tend to be bulletproof and lighter granites less so. Although I have a white granite that is totally bulletproof and maintenance-free, so there’s no perfect rules.
Anyway to the OP’s original question, the type of cooktop really depends on the intended use and how you cook. If you don’t cook much then any old thing will do. If you wok you’ll want a high-BTU gas range or rangetop in the 15k+ Btu range (per burner). Although since you mentioned downdraft I suspect you won’t be wok’ing much as you’d smoke yourself out of the house. If you simmer a lot, especially delicate sauces, check the btu of the simmer setting, as high-btu plus low-btu on a single burner doesn’t always compute. Some rangetops have a special low-btu burner for simmering, while some like Wolf have a special stacked arrangement that supports both, or at least they used to.
If you like to have several pots going at once and move them around while cooking, then get a rangetop which has identical output from all the burners (although some have a special high-output wok burner). If you’re going electric then induction is great but you may need new pots/pans to work with it.
If your oven is below the cooking surface and you have gas then you could get a range, but then you have to choose between all-gas vs dual-fuel. Dual-fuel being significantly more expensive but baking with gas kinda sucks for serious bakers.
For brands I have a Viking rangetop and don’t like it (it’s been unreliable and Viking wasn’t very helpful). I do like Wolf and Dacor. Thermador I’m kinda iffy on, they’re just meh in my book. Jennair I’d avoid. I like kitchenaid appliances in general but have never had one of their gas ranges.
