That's exactly what I thought. About ten years everyone is rushing to distribute large downloads in xz format. These days some have started to move away from it just because how slow it is to compress and decompress.
And importantly, that 32-bit checksum is a pretty good checksum; a truncated XXH64(): https://tools.ietf.org/html/rfc8478#section-3 That's about as high-quality as you can expect from 32 bits. It's not, say, Fletcher-32.