Im not going to go into technobabble here but
The carbon question
Trek technology is old i wont go into details
The aluminium question
a forged part is stronger intrinsically provided it is a part which has been designed to be forged no sharp radii etc added to this you must ensure that the correct alloy is used Just because its 7075 the supposed strongest alloy does not mean that it will be stronger forged 7000 SERIES ALLOY suffer SCC.
There are special alloys with properties geared toward forging that although on paper they seem slightly weaker are much stronger when forged in terms of fatigue.Fatigue or stress corrosion is what makes very high tensile aluminiums fail
The other thing is that most suppliers have little access to so called aerospace alloys and by this i do not mean certified i mean altered metallurgy, only slight in some cases ut it makes them unique.they do vary from commercial alloys.
on top of that you have post processing ,you think anodizing is good? think again it allters surface properties in a way that can induce failures ,most companies claim they know how to manufacture good alloy parts but in truth their post processing is far behind the techniques used in aerospace or even high performance motorsports
Unfortunately if most of these good techniques were applied the part, cost would spiral to a point meaning commercial products were out of our reach.