Absolutely. As you're noticing, trying to compress a 2880px tall video down to less than half that size at 1080px tall tends to make it a bit blurry. But, all is not lost, if you can't record again at a lower resolution. You can zoom and pan around your video to see the parts that you need to focus on. So, for instance, if the interesting thing you're trying to show is in the top left of the screen, you could zoom in to 100% size (or, perhaps 50%, a nice even number that's easy to resample to without losing as much quality as the 37.5% you're at now), in that corner.
You can do this by adding a 'custom animation', then setting the scale and position of your video in the canvas until it looks the way you want (do this with your playhead to the RIGHT of the animation). Just keep scaling in/out or panning around to focus on the important content.
That's the best I've got if you need to use your original, large recording! Hope it helps.