Some user group comrads from a classic road bike group reported surprise at what they found in town after town (with bike shops) after they'd gone to the expense of shipping their vintage steel bikes to Italy for credit card touring. (Their bikes were primo brazed and filet brazed steel, within a few lb of minimum unsupported weight of road racers of the day, the day being pre-1983. Say 20-22 lb.)
Hanging out at the shops were old men like me, very fit riders (unlike me) in current team kit, not classic stuff. Their bikes? Copies of current carbon-fiber (CF) frame, CF-wheeled bikes, saving 3-4 lb, some outfitted with enough gram-saving components to bring weight to the current racing authority mandated minimum of 15lb.
If they want to compete going up mountains-- and they do with each other and with younger riders in the club -- they don't want to haul an extra 5lb up mountains while putting out 200-250 watts. And they could care less if the bike -- the CF frame and wheels especially --last more than a couple of years, because next years models will be at least 5% and maybe 10% lighter.(No lower limit on bikes not used in competition.)
The point of saving is to have the $3000 to buy a new frame and wheels every couple of years, because at 65-75, that isn't going happen too often. Every purchase the last several years could be counted on to save at least 3-4 oz / 100g.