There was a poll a few years back asking Patreon subs if they wanted meatier content with longer dev time or shorter content with shorter dev time. The former won, so that's that.
Plus Cari mentioned around 0.6 that he wanted to pace his dev time to a more manageable sched so as to prevent burnout, hence the added dev time to an already lengthy sched. While that may sound unfortunate for those waiting for the updates, IMO if it eventually leads to him seeing the game to completion instead of noping out and becoming another abandoned game then I'm all for it.