Keith Bontrager famously said Lighter, Stronger, Cheaper referring to the fact you can only have two out of three (i.e. If its light and cheap it wont be strong , if its strong and light it wont be cheap and if its cheap and strong it wont be light) This still bares true for main stream manufacturers components where there is a massive margin of safety involved.
However there is a growing market for extremely lightweight equipment that is light and very expensive, should this be strong too?? Well it pushes the boundaries so no this is cutting edge light weight equipment. It should be used with extreme caution and for very specific events you simply cannot expect (for example) a 12gram bottle cage to support up to a kilo of water as you bounce across cobbles.
Also there are lots of forces involved in cycling so if you insist on ultra light equipment don’t cry when your wheel collapses if you hit a pothole at 90kph. Crashes and impacts put massive strains on components, these forces can’t be anticipated but the lighter your stuff and the heavier the impact the greater chance of failure.
Likewise a racing tyre that has puncture protection is not a puncture proof tyre, car tyres puncture, a 190g tyre with a micron of Kevlar sheet in it will not protect you from glass and the law of averages state you will run over that glass within 3km on your first ride.
I have some lovely lightweight stuff – I have an ultra light bike for impressing my mates and it’s a joy to own and use but my race bike is a sensible 17lb. There is a case of too light, buy the good stuff, relish in its weight and the beauty. Take a picture of it on the scales, enter a hill climb but unless your a 8 stone rake, climbing in the alps proceed with some caution. Check components regularly, use a carbon prep and a torque wrench and just accept that ultra light weight is just that, and all that glitters is not gold….