GIF maker for 18.04 without losing quality

I am looking for a GUI tool like GIMP to create animated GIFs from PNGs. I tried GIMP 2.10. The quality of GIF is low in it. Perhaps to reduce the size of GIF, but there are burrs on the side of the GIF (due to low image quality).

For example, here the edge outline has burrs, base image was clean:

I tried a few online convertors and Photoscape in Windows. Online tools had even less quality and Photoscape gave almost the same quality as GIMP.

I know there is another question which talks about ImageMagik. But kindly avoid suggesting CLI tools. Hoping to find a suitable tool.

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