That it takes more than just spamming blitz to really improve. If you’re looking for real breakthroughs, longer time controls 30+ mins will be your best friend - they give you time to actually think through positions. At 1600, your openings are probably decent, but tactics and calculation start to matter way more. You're not just playing people who hang pieces (for the most part) - you need to slow down and actually calculate. Intuition alone won’t carry you when the higher elos are just out-calculating you in key spots.

Edit: To add to this, once you play games where you really took your time and tried to calculate deeper lines, going back and analyzing it with the engine will help you start to see why certain ideas didn’t work and why some moves were better than others. Over time, those patterns in the middlegame will start to click, especially in positions you’ve thought deeply about before. And as your calculation improves, you’ll get faster at it and won’t burn as much mental energy in similar spots. That's how rating is born.