You contradict yourself in the first 3 sentences and then again shortly after. How can something be too chaotic and fast, but also take 20-30 mins to organize? How can recruiting chat both take too long that the simple act of clicking on a name and trying to type out 3 letters take TOO long to get an invite to a group that is already full? Is it really so hard to figure out that if your DM that says "inv" doesn't get a response means that the group is full?
I don't disagree that it's outdated and old or whatever, but I do disagree that it isn't sufficient. It's definitely good enough as I was able to get a group of 3 others to farm for Axi relics in Lua Disrupt within about 2 minutes after posting in recruit chat that I needed 3 more and this was DURING today's chaos with the chat flying as quick as it is. I only ever really struggle to get groups for vaulted radshare relics.
As others have stated already, you have tools to mitigate your issue in the meantime. "The meantime" might actually be "forever" as I doubt this is even on the radar of things to fix.