Wow, I didn't know there was such a thing as a bag freak, but you have opened my eyes. BTW, I know you are real smart!
I have lots of bags, but I'm not knowledgeable. I found a review of a Timbuktu bag by a guy who obviously was deep in bags and travel and he liked it for traveling, like a single bag trip to Europe or whereever. He had IIRC a couple of videos that I studied carefully. I found a great deal on it and bought 4 of them! Yeah, so I have extras. I like it for a weekend jaunt via plane somewhere, i.e. family gathering. It's an adequate carry-on. Tough, not full of separate compartments. I have a couple of bags like that and since I am not a frequent traveler I found myself not remembering what went where sometimes and that's a problem. The Timbuktu is one giant compartment with slots and a zippered compartment or two and flap-over, some velcro. It's pretty water proof, not super light at all, but what's 8oz extra when you're traveling?
I have several other backpacks, all kinds. One I prefer for rollerskating, I bought special straps for it. I have one giant one I use for grocery shopping. I have backpacks from 30-40 years ago I just haven't seen fit to discard. I have repaired packs many times. I even have a fanny pack that I don't use, well, maybe rarely. I bought a water hydration pack a couple years ago I used on my skates at Hardly Strictly Bluegrass Festival, roller skating. That was nice. I used it for a 10 mile hike into the hills a 2-3 months ago, it's nice, can put a few things in it besides the water.
Being a bicyclist for many years, packs make sense. Also, I didn't have a car for 20 years straight. Packs were essential. It's a habit I haven't lost at all.
I still have the external frame pack I took to Hawaii in 1970!