I didn't say first, I said responsible, and first doesn't really matter. Albert Einstein's e=mc^2 wasn't first, it was already published by someone else written slightly differently. But he made it popular, and that's what counts for widespread adoption and propagation of tech.
You sound like an older hardcore nerd. You're from a different planet. What was going on in your circles was not at all a reflection of the web on a whole. Most people didn't even use ISPs in those times, they were on private systems like AOL. The dynamic web we know today, where almost every website is not static HTML, is because the majority of people making any little website had access to PHP, and free tutorials to learn.
Before PHP became widespread in the very late 90s there were many options for dynamic apps. I worked with ISPs which offered CGI or SSI even on cheap / free plans. Sure, it was ugly but a ton of people got what they needed done by going over to Matt's Script Archive and finding something they could hammer into shape. Before antique PHP apps, the security cliché was formmail.pl & a slew of long-forgotten guestbook / forum scripts.
I'm not saying that PHP didn't help considerably, only that it was very far from first. I remember having to make the case for using PHP 2 or 3 instead of many of those alternatives and it was based on cost and convenience, not the ability to do anything new.