nostr:npub1tr4dstaptd2sp98h7hlysp8qle6mw7wmauhfkgz3rmxdd8ndprusnw2y5g wrote this extremely good article for bitcoin magazine about ARK (and spark). Def worth reading a few times to get your head around the tradeoffs.
https://bitcoinmagazine.com/technical/spark-and-ark-a-look-at-our-newest-bitcoin-layer-twos