tl;dr: Use svgo to minify SVGs.

brew install svgo

wget https://upload.wikimedia.org/wikipedia/commons/a/a9/Amazon_logo.svg

svgo Amazon_logo.svg

Amazon_logo.svg:
Done in 18 ms!
5.4 KiB - 35.4% = 3.486 KiB

The svgo tool was able to optimize the file by 35%; this is a material improvement.