How to make (round) icons look smooth/anti-aliased?

Hello,

I designed some vector images, but the SVG Importer seems to sort of just convert them into bitmap images. Anti-aliasing works fine for larger bitmaps, but I have found no way to make smaller icons look good. They always end up looking jagged or deformed (also tried with regular PNGs).

Here's an example of a some icons (not mine) in portrait and landscape view. The quality noticeably decreases when they get scaled down in landscape view (final game will be landscape only).

[1]: /storage/temp/195879-buttonsportrait.png

[2]: /storage/temp/195880-buttonslandscape.png

What am I doing wrong here? I'm using the URP.

Edit: I got the icons to look much better by first downsizing them in an image editor before importing them into Unity (as PNGs). This way anti-aliasing can be turned off in Unity and the quality stays good. It's not perfect but it'll do!

Edit 2: I managed to further improve the quality of the outer edge by, rather than using a round sprite, using a square sprite with a circle mask and cutting off anything beyond the mask (making the sprite look like a circle).