I was in a very similar position as you. Thirteen year user, moderator for a few smaller subreddits, including one that provided support for a US-based mobile phone carrier, and deleted everything when the API change happened.

It took time and effort to coordinate and help uplift those who generated the great content for those subreddits, but Reddit, Inc., was unwilling to help us moderators who had developed and used the tools necessary to do it. I wasn’t willing to put in the additional time since Reddit was themselves unwilling to, post API change.