Frankly, I think you are asking the wrong question. "Please give me some reasons to buy a new scope. (Again, less than a year after I got my current one.)"
I would suggest that you focus on actually using your current equipment for a while. If you should run into resolution limitations (which the enhanced resolution mode in the X plus cannot work around), start thinking about a 12-bit scope. By the time you will also have learnt more about other features that are important to you, to guide your selection of a new scope.
EDIT: Oh, in case you cannot resist eventually: Get out the tape measure before you buy a 3000X HD (or a 2000 for that matter)! It's a bit taller than the X plus, and looking at the photo in your opening post, I am not sure it will fit into the current shelf space.
Okay, let's imagine you're a traveler with your car. Perhaps you already own a regular car. However, there's also the possibility of acquiring an F-segment car, such as a Mercedes S-Class or similar.
You can't fully exploit its speed potential on everyday streets. Nonetheless, on the German Autobahn (with no speed limit), you could unleash its capabilities, placing your trust in its performance.
In my situation, even though I'm not an F1 racer, I still enjoy the benefits of driving like any other driver, and I have complete confidence in the car's abilities, even at high speeds.
I am just a traveler with my car...
We are talking a bit about luxury then. I honestly think the 2000X-HD is the top hobbyist general purpose oscilloscope, it is already quite a "luxurious" tool, or way better than necessary but still nice to have.
To take full advantage of the 3000X-HD you need (pretty expensive) probing solutions. I don't think it is a good buy for someone whose budget is actually the oscilloscope's price.
That being said, there are hobbyists that buy professional stuff way over their needed level. IE, tens of thousands on road bicycles, festool track saws, fishing or hunting equipment, Hilti drills, handmade luthier instruments, etc. I, myself, have tools with capabilities way over my skill level on quite a few areas.
Still, I wouldn't go over the 2000X-HD, as it seems to me it would only be nicer, and not actually more useful, but that's just me, it's a decision only you can make.
EDIT: that's probably a bit of an arbitrary limit, but when a scope needs higher spending on accesories than on itself, it's out of the question, for me. But, as a matter of fact, many of us are spoiled, having everything necessary for living, all the tools needed for our jobs and, on top of all that, an additional fully featured workspace just for pleasure.
So the difference is quantitative. Qualitatively speaking, it's all luxury anyway. I just think setting oneself limits is actually quite healthy.