Do compression packing cubes actually make a difference, or just reorganize your suitcase?

I’ve always packed the “layer everything flat and fill the gaps” way in a hard shell suitcase, and it’s worked fine for me. Clothes get squashed down evenly, and I can usually use every bit of space without much waste.

Lately I’ve been seeing more about compression packing cubes specifically Tilliv ones, and I’m trying to figure out if I’m missing something or if it’s just a different style of packing.

I’m not against trying something new just trying to understand if it’s genuinely more efficient or just a different way of packing the same amount.

Would love to hear from people who’ve used them for a few trips, not just once.