I think it is also a historical coincidence. Cyrillic is an original Slavic thing and its early variant Glagolitic srcipt (https://en.wikipedia.org/wiki/Glagoli

I think it is also a historical coincidence. Cyrillic is an original Slavic thing and its early variant Glagolitic srcipt (https://en.wikipedia.org/wiki/Glagolitic_script https://en.wikipedia.org/wiki/Glagolitic_script) was actually created for West Slavic "customers". It was later replaced there by Latin script simply because early Slavic states there lost their independence to Germanic states. Since early literacy was a rare thing reserved for small clergy and state official circles, and since Slavic population has limited access to those, it was a natural thing that it died down in favor of Latin alphabet.