I would never suggest archiving unless we're hitting some performance limit. Why generate more busy work? Just leave it there and if need be add more indexes and partitions.
And several of these "columns" were actually JSON blobs that probably should've been in their own table. But what do I know. I left!
Once you have an existing tirefire, it's a matter of damage control and "what is the least bad way to accomplish new functionality?" and the answer to that will always be unique for each unique tirefire.