Pricing structures have also changed, though.
I grew up in a seaside resort and we had a big fairground on the promenade. It was "open" to all, no need to pay an entry free, but instead, you bought books of "green tickets" which you exchanged for rides, with smaller/simpler rides requiring only a small number of tickets, but the big ones requiring a bigger number. I seem to remember going at least weekly during the season, sometimes 2/3 times per week. My mother would give me a relatively small amount of money for me to buy a "cheap" book of tickets and then I'd choose how to spend them, i.e. whether to blow them on 1 or 2 "big" rides, or go several times on the cheaper/simpler rides. Never spent long in the fairground, usually just an hour or so. A "day entry" ticket, akin to modern pricing simply wouldn't have worked for us. Years later, they changed it and turned it into a "theme park" where you paid a day entry ticket and could have unlimited rides on anything. It didn't last more than a few years before it closed down and is now a derelict eyesore!
When our DS was little, we took him to various small seaside towns and would often find the "old style" fairground (often travelling fairground in a park etc), where they still used the old ticket system and it worked for him too, as we could just "nip in" for an hour or so, he could have a few rides, and then we could go again later and do the same, so as to spread out the entertainment over 2/3 days instead of blitzing it in a day. Also worked for us as we didn't want to go on rides all day, so didn't have to pay our own entry fees that we'd never get monies worth for.
Really annoys me with the modern "day entry" tickets. Even abroad, we went as a foursome to places like water parks, etc., me and DH, my mother and our DS. In, say, a water park, we'd have to pay for 4 entry tickets, but my mother never went into the pools/slides etc so a complete waste for her to pay to just lie on a sun lounger. DS was mostly too young for the big slides, so just did the pools and lazy river and small slides, so not really worth it. Me and DH didn't like the big slides, so we didn't do them either.
I do think the "day ticket" pricing puts a lot of people off, but maybe it's the only way these attractions can generate enough income to cover their costs. When you see how many have closed down (obviously not the big ones like Alton Towers etc), but lots of smaller fairgrounds and indoor water parks etc have closed down, even high charges don't seem to be enough to cover the ever increasing costs.