If I were to list anything as having caused the demise of pool, I'd say tougher and tougher dui laws, making even normal social levels of drinking
prime targets for dui's. Many places you can get a dui at any level, not just .08 and above, and zero tolerance is the name of the game now.
It used to be you could go every week, have a couple beers, play your matches around the city wherever they are each week and go home safely no problem. But now if they don't get you for a taillight out, if they're not getting you in random roadblocks, if they're not following everyone out late at night, they are stalking bar parking lots just looking for potential revenue.
Find me one BCA or APA team without at least one person that has had a dui and you should get a prize, it's a rare thing not to have several people per bar that have gotten at least one and then weekly driving to bars around your local area becomes nearly impossible and quite a bit more risky.
I don't think people are giving up pool because they want to, they are giving it up because they've had to, and fewer and fewer people are getting their feet wet starting in the bar leagues and the typical way because of that dui limitation, it's constantly a worry and a hassle for everyone and on everyones mind and just not something you can always work around. Over 1.5 million dUI's are given out per year, that's a shit ton of dui's. We are not talking about just drunk drivers, dui's affect anyone who drinks at any level even one beer can get you one you don't even have to fail a sobriety test, if you drink and drive you loose period is the motto now.
Sure there are cabs if people could afford them all the time, but you'd have to be able to afford one every week.. Sure there are designated drivers, if that weren't an impossibilty for many to commit to that on a weekly basis. And sure there's public transportation, in some places, at some times of the day not so much late at night in most places.
More dui's = more death of the game... Non drinking atmosphere pool halls don't have the draw of the sheer numbers and variety of people that bars always have had in the past, and if you don't get that foot in the doorway of pool competition in bars you probably just won't get it anywhere these days ever. So less players forever in the future unless there comes a better form of transportation across the whole country for the average broke person that doesn't leave them open to dui, yet does allow the freedom to at least drink social conservative levels to get that foot in the door and started on the path of actually learning the game and giving a crap about whether it's on tv or not and knowing enough about it to find watching it interesting or betting on it worthwhile.
Maybe by the time we have self driving cars, all of them even for the average person, bar pool leagues bca and apa and all the levels above it will come back in popularity. Not until.