I was around for 10 years on the old forum, but I honestly don’t miss it that much. Every once in a while, there will be some aspect of it that I miss, but nothing major.
It does seem like the flagging system is used differently that the reporting system was in the old forum, but I’m honestly puzzled as to why that is. I treat the “flag” in the exact same way I treated the “report post” icon" that was also available in the corner of every single post in the old system. I only use it when I feel like the situation warrants it, which isn’t that often. The only difference is that, with the Discourse platform, a certain number of flags will temporarily hide posts or shut down threads. It still requires moderator action to delete posts and lock threads, though.
I think the changes that were made were most likely out of necessity with a view to the continued sustainability of the forum. Forums in general have dramatically declined in popularity in favor of other platforms like Facebook, Twitter, Reddit, etc. I know of a lot of forums that have simply closed up and/or become ghost towns because that’s not where most people are carrying on with their online conversations nowadays.
So while I probably most miss the presence of moderators who would generally be able to step in and right the ship before threads got too bad, I have pretty much come to terms with the fact that the forum simply couldn’t continue under that model any longer without a huge influx of donations that simply aren’t there.