The buyer will change the carpet/cupboards to whatever they want...
No they won’t...what they will do is reduce the offering price to include the new carpet or cupboards (at a stupidly exorbitant rate)!
I’m not suggesting you replace all your carpeting or remodel your kitchen in order to get a good offer on your house but I am suggesting you be realistic. No matter what the asking price of the house is, the buyer is going to be paying out a lot of cash to make the purchase happen. Purchase price, insurance, title costs, lawyer fees, disbursements, moving costs all add up in the buyers mind...the last thing most buyers want to do is plan an expensive reno before they have even bought the house!
Here are some suggestions: if your carpet is threadbare...check to see if you have hardwood floors underneath...if you do...get rid of the carpet...give the hardwoods a good clean and Bob’s yur uncle! If there are no hardwoods, consider area rugs, laminate flooring or yes, replacing the carpet. If your carpets are in serviceable condition...just give them a good clean...stretch them back into shape if necessary and you’re done. The goal is to stop the buyer from adding up costs in their heads and discounting your asking price.
Cabinets? The same story. If they are in really rough shape...do your best (or hire a handyguy/gal) to repair what you have. A vigorous cleaning, a coat of good paint & some new hardware is a really inexpensive way to give a kitchen a face-lift. Other thoughts...just replace the doors...or go with no doors and dress the kitchen-bistro style!