There are so many factors in play here.... I'm old. And, old school- although, I was wiring in HF drivers in my bass cabs long before SWR started doing that.. that said, I used to carry an SVT head on occasion- on the N.Y. City subway- no hand truck or dolly- or anything. Did I also say I was nuts when I was in my early 20's. Yeah. But I knew no one would try to steal it! lol! I remember in the time before the nightmare of Rap and hip-hop suckled and nurtured kids grew up to be sound people, and went mad with overpowered subwoofer kick drums at every gig, concert, and even rehearsals. I remember when stage mixing was the order of the day. Guitarist has a Deluxe, small drum set, in a small room? You- A B-15, B-25, Fender Bassman, Kustom 200 or other relatively (by today's standards) lower wattage amp with good speakers would work well. Add another guitar, maybe a Twin Reverb, and a keyboard player with a Rhodes, a JC 120 or another Twin- and maybe a half stack - and you went out and got a V-4B, Showman, SVT, Acoustic 360, 370 or Sunn with a couple of JBL's. PA stuff was pretty awful- the ubiquitous Shure Vocal Master, with its pants tearing 'L' shaped scar on your calf -producing aluminum trim pieces, would be howling along at a hundred distorted solid state watts of feedback bummer.
Fast forward a little into the late 70's, and the PA with a power amp/ mixer, and high quality speaker cabs with bi-amp capabilities, improved things greatly. Again, the fast forward- then, Subs became more and more common.
"Please, Mister Soundman, do not bury the bass under the kick, o.k.?"
Soundman hates that you even addressed him- and not only buries you in the house, the kick is so loud, and deep, you can't hear your amp onstage either.
So where are we now? Combos, or no amps at all onstage. I was in a band where the bandleader who claimed to love bass guitar, denied me an amp onstage. Instead, mixed the entire band, with drums, synth, keys, guitar and all vocals.. and me, through two Mackie two 15/horn PA cabs, and one Mackie sub. The band was really good, and a lot of my friends came to see us. Quite a few bass players. All of them said the same thing. " I had trouble hearing you" -or, "I couldn't hear the bass at all"
Bandleader, "I had you pumpin' out there" Yeah, sure you did. THAT is the mindset now- we are not often in a self-mixing situation anymore. I've been told a small combo is all I needed, and ended up having a really unpleasant gig experience. Frankly, I literally gave up asking the sound people for anything other than a DI line to my Zoom B-3, and where is my specific Aviom, or Power Play mixer. If I have to bring an amp- I'll bring a pretty powerful head that'll run at 2 ohms, and two cabs. I'll set it all up, and if I don't need both, one cab will do, and one stays in the trunk of my old Caddy.
Reminds me of Dickens' line- "It was the best of times, it was the worst of times" Seems as bass players, we have the BEST times- more choices and options now, than ever. BUT, the ultimate sound we project, is often completely out of our control... the worst of times... the irony.