My 8' Thomas Light Special 4/5-wt is 4.0 oz. The weight is insignificant because of the extremely fine tips.
This is also the same weight as 9' Sage RPLX-7 Graphite III.
Hollow-built butt sections can lower cane weight dramatically.
I fish a gang of 8-1/2' for tailwater, and they push 5 ounces.
My 8' Leonard Fairy Catskill from 1915 (Line G - 3wt) is 2.7 oz.

Much heavier is inaccurate. 9' cane pushes to extreme.
But the most boat-anchor-rod I've ever handled was Shakespeare 1280-T glass, 7'9" - the tip weight is outrageous.

Tip weight is a big factor. My long inshore conventional rods (Toray graphite) are typically 5 oz, but you don't care with lightened-tip sections and titanium-frame microguides.
With these, you're casting lures continuously. If you're casting a fly rod continuously, you're doing something wrong.

For the same length and line weight, most recent glass rods are going to be lighter than bamboo. Vintage glass varies quite a bit. Some are nearly as heavy as bamboo - early Phillipsons with nickel silver ferrules for example. Others, like Fenwick and Berkley Parametrics with glass tip-over butt ferrules are as light as much modern glass. Some cane rods are impregnated (Orvis for one) which increases the weight a bit. Others are hollow built which decreases the weight. And to complicate the comparison further, recent glass can be e-glass or s-glass (which is usually lighter). So, as the others have said, it's hard to generalize.

Massive bamboo (unless hollow built) vs fiberglass tube?
Sounds easy to guess

Bamboo rods are somewhat heavier than glass and bamboo also has a higher modulus than glass.