As someone who has been meal prepping for decades, I can tell you the secret is variety in texture and temperature. Staring at the same cold container every day is bound to get old.
My method is to prep a solid base, like grilled chicken strips and roasted sweet potatoes. Then, each day, I add a 'fresh element.' On Monday, I might add some fresh avocado and a squeeze of lime. On Tuesday, I'll add a handful of spinach and some crumbled feta cheese. On Wednesday, maybe some crunchy sliced almonds and a dollop of plain Greek yogurt. This way, the core of the meal is ready, but you get a little something new and exciting each day.