WhateverBB style PHP forums were never good. They were always regressive technology. Don't pretend something is good just because what we have now is even worse. The user interface was terrible. I don't miss clicking a tiny 10 pixel wide button to go to the next page. The search was always disabled due to high CPU usage or had some major issue. There were RCE exploits galore (largely due to PHP and webshit). Moderation was crap because it was centralized and in practice some loser's opinion. Every single forum I've ever visited had users with 100K posts who are banned because one of the moderation fellas felt like banning them one day despite that 99% of forums are about a topic as opposed to a community.

There's also the fact that these forums tend to exhibit an inner platform effect. For example warez forums. Instead of having a dataset built by multiple parties that provides links to scene releases, you'd post your links in a forum and needlessly make a giant page containing the product title, some stupid copy pasted description of it, maybe the NFO, maybe a plugin to display NFO directly on the page, etc. Then you'd have users who beg for thanks or put their stupid branding on their content, for example I remember a user on a warez forum who felt the need to mention chemtrails and the illuminati in all of his posts.

The said forums contained a sea of useless metadata that nobody uses on top of avatars and profile fields that you could spend hours going through. Same for configuration options. Since they're webshit and you have no control over what you see save if you build some screen scraper which will bitrot eventually, all it took was one moderator to make a stupid color theme and you can no longer discuss the topic at hand without straining your eyes.

Singing up to any of these forums was completely standardized: it usually only requires username, password, email, and captcha, and then the email has a 40% chance of arriving in your mailbox. The boneheaded type of person who moderated these forums were the same type of people who vehemently insisted on email verification because they haven't even thought it through enough to know that it doesn't stop spam (yes, the reason was "stop spam" and not "recover password").

Basically, these forums were a shit ton of overhead to support the very basic use case of having an anonymous discussion over the internet.