I regret to inform that not a whole lot has been added since then. The Fields (next major area) was promised back in 2018 but only came to fruition last year, as a result of Inno's procrastination and tendency to get getting distracted by side-content (some of which was unplanned) and minor NPCs. The companion system was abandoned (you can still enable it, though at your own peril). I made a post about what was really done over the years (though I didn't continue past mid 2021).
You can see it here.
According to some, the quality of the writing has deteriorated and some of the new NPCs are either too niche to be enjoyable or at least pander too much to minor crowds, making it debatable whether or not the amount of time spent writing them was justifiable at that point in time. Also, Inno's progress has been slowing down more and more each year. Some attribute it to personal problems, such as lack of motivation, others say the code is becoming a tangled mess that is making it harder and harder to add content. I think both arguments are true.
Right now, it has been 2 months since the latest release (3 months, if we count the latest free build) and we're back to delays after delays and delays for the delays. The last free update was in February, the last preview update was in March, she made two posts after that and then radio silence. Her last post in SubStar is from March (meaning she wrote an update on the blog but didn't post anything for her subscribers). And yet she is relatively active on Discord, but only for off-topic stuff...