a 65L pack IS very large. I do 10 day trips (including a bulky bear can) with a 55L pack. When I do 14-day backpacks I use my old Kelty that I have reduced weight to 3.5 pounds be sewing my own UL pack bag.
The kind of trek you talk about is not what is considered typical backpacking.
The new packs assume you have some of the new lighter and more compact other gear. The "600-" sleeping bag, assuming that means 600-fill down is now replaced by 800-900-fill bags which pack down a lot smaller for the same warmth.
As for ground cloth, a home-made Tyvak footprint is lighter and more compact. Personally, I think it is marketing hype, to advertise a tent as "light" then have the floor so fragile that you have to add a footprint. If the footprint is really needed, then the total weight and bulk of the tent really should include the footprint.
There are UL compression stuff sacks (very expensive, though) that I use for my clothing (except my down jacket). You can really squish wool a lot without damaging it.
You said nothing about food. As for cook gear, it is easy go overboard on this- one pot, each person a cup and spoon, and eating communally out of the one pot saves bulk of too much cook gear. Food varies a lot in bulk, for example elbow noodles (bulky) vs cous-cous( very compact). Freeze dried meals are light but bulky.
Getting the bulk down requires re-thinking every piece of gear. For example, one small 1-oz single blade knife, vs the Swiss Army knife. Perhaps too much first aid gear?
That said, I am not a fan of Osprey packs because they seem to have compartment sizes that, for me, are not fully usable. Two 65-L packs do not necessarily have the same useable volume. Particularly if the outside pockets do not expand enough to allow for fully packing the inside compartment of the pack. And for top-loading packs, some manufacturers count the extended top closure part in the total volume. However, if you really pack it all in that high, I find that the weight balance in the pack is very awkward. Some pack "lids" are odd sized- somehow just do not carry the items I want available very well. Side pockets on the hip belt also are sometimes awkward. Also, some pack's volume include (assume)lashing on some gear.
I do not pay much attention to those reviews and lists of the "5 best" or whatever for any gear. But I do think that you have a lot of ways you can reduce the volume of your gear.