nostr:nprofile1qqs8fl79rnpsz5x00xmvkvtd8g2u7ve2k2dr3lkfadyy4v24r4k3s4spz9mhxue69uhkummnw3ezuamfdejj7qg4waehxw309aex2mrp0yhxgctdw4eju6t09uqsuamnwvaz7tmwdaejumr0dshsu0ur8h has some good YouTube videos on this.

TLDR- more knots nodes means it takes longer to propagate blocks containing spam, while a competing block that does not contain spam will be accepted by the network much quicker. So miners adding spam to their blocks run a higher risk of their block getting orphaned and that risk goes up with knots adoption.