Big sprites look bad on small screens

[pingu]

On Unity, I used to make sprites for the largest iPad that my game needs to support, and everything would still look good on smaller devices.

But in Phaser 3, I notice that when large sprites are scaled down to fit into smaller mobile devices, they looks very zigged and aliased. Is there a way around this? Do I have to create sprites of multiple sizes and choose the right ones depending on the screen size? It is also recommended that sprite size be multiples of 2 - 256, 512, 1024, 2048, etc. It would still be very approximate to use the nearest power of 2 sprites depending on the screen size. Any advice?

Regards