Aluminum is approximately 66% lighter than titanium.
Well, yeahhh... strictly when comparing nuggets of equivalent displacement. Keeping in mind that both aluminum and titanium both must be alloyed for most practical applications: Aluminum commonly with manganese, magnesium and silicone; titanium commonly with iron, nickle, aluminum and tin.
Titanium has awesome strength-to-weight ratio; weaker aluminum has better electrical and temperature conductivity. Both have soft surfaces in clean raw form. Outer oxide (or other elements) coatings give them surface hardness, which can be near diamond-like.
But we're talking about fashion, here, and all that matters is that titanium is a wonderful material and finish. In a laptop or phone chassis, titanium is strictly a pretty veneer, grafted to aluminum. Titanium is hideously expensive to produce; no one needs or would feel value in a solid titanium phone chassis. And as mentioned, it wouldn't manage heat well.
As for the phone back panels, I always thought glass is stupid - a fragile, often fatal, weakness introduced on purpose! Humbug! I'd prefer modular plates, screwed into place with a nitrile gaskets, plus whatever plastic gutters for antennas - because of course, the BATTERY WOULD BE USER SERVICEABLE. Anyway, laptops are ready for such next level aesthetics.
They could just anodize the panels in pretty colors, and everyone could sell more backplates with designer art or finishes. And the plastic antenna gutters could be light conductive plastics, so they could play status or music light shows better than Nothing Phones do - customizable with data from apps and feedback from sensors from iPhones or Apple Watches. Not entirely unlike showy PC case builds.
If Apple wants to keep their branding on display (not in protective cases), on the hip or arm, in hand (not in pocket or bag), or on desktops (not on floors or hidden behind monitors) then they really need to ascend past neo-brutalist bricks with fragile, mild color tinting. You should be able to put your phone or laptop on the bar, and get a free drink for the coolest case & lighting each hour. Remember white iPods and Earbuds, folks getting down with that white cable swinging? The candy color MacBooks? No? Errr... Apparently I'm old AF. But Apple needs to do THAT again.
