I cannot find any good explanation about these 2 statements about reorg:
1.Reorgs can increase the number of nodes within a blockchain over time, causing a poorer user experience.
Why reorg increases the number of nodes?
2.When reorging becomes more common, attackers only need to beat a portion of honest miners (due to the “longest chain rule”) rather than all of them.
Why is this so?
1.Reorgs can increase the number of nodes within a blockchain over time, causing a poorer user experience.
It doesn't. The statement doesn't make sense. Likely the source you are citing is incorrect.
2.When reorging becomes more common, attackers only need to beat a portion of honest miners (due to the “longest chain rule”) rather than all of them.
Ethereum doesn't have the longest chain rule, but the heaviest chain rule, so this statement needs to be rewritten for Ethereum. Thus, this rule is probably about Bitcoin and other proof-of-work chains that rely on longest chain rule. However, without context, it is not good to have security related discussion.