I'm agreeing with you about venues wanting to pay less and less. I gave an example in my first reply (last week). I get it.
It's inaccurate to say that it's killing the bass player. It's killing the traditional bands, as you pointed out, in smaller towns. To be more accurate, it's killing the traditional professional bands. The weekend warriors who don't mind playing for $150 are doing just fine. Those bands have bass players.
There are more people in the world than there was 30 yrs ago. There's a whole lot more emphasis on "making it big". More people following their dreams. All around the country, each area has become saturated with bands. Technology has made it easier for the DJ to put on an entertaining show or for a solo act to loop a rhythm while they play some lead.
Don't think like the railroads did when the airplane took over. They kept thinking they were in the railroad business. They didn't realize they were in the transportation business so they didn't adapt.
Stop thinking that you're a bass player. You're in the entertainment business. It's not about the musician. It's about the paying customer. They want to be entertained. Be entertaining and you'll succeed.