The egoism/altruism distinction makes sense in the framing of boundaries and scopes of optimization for different preferences. If you optimize things that are centrally yours (within the boundary of what is you or yours) according to values of egoism, and optimize things that are centrally not yours (outside this boundary) but within some circle of concern according to values of altruism, this is a healthy state of affairs. (Enemies could form yet another scope of optimization, with values of coercion and such.)
This works for interventions that either mostly affect things on one side of the boundary or the other, but breaks down when they significantly affect both, when there are tradeoffs. An important failure mode (perhaps downstream of having to deal with situations that have tradeoffs) is when values appropriate for one scope of optimization get directly applied to another, when egoism or coersion target your circle of concern, or altruism gets turned back on yourself (or enemies). Or when the boundaries get redrawn in a strange way (someone with a lot of power could consider quite a lot of other people “theirs”, applying egoism, optimizing for effectiveness without respect for autonomy).
The egoism/altruism distinction makes sense in the framing of boundaries and scopes of optimization for different preferences. If you optimize things that are centrally yours (within the boundary of what is you or yours) according to values of egoism, and optimize things that are centrally not yours (outside this boundary) but within some circle of concern according to values of altruism, this is a healthy state of affairs. (Enemies could form yet another scope of optimization, with values of coercion and such.)
This works for interventions that either mostly affect things on one side of the boundary or the other, but breaks down when they significantly affect both, when there are tradeoffs. An important failure mode (perhaps downstream of having to deal with situations that have tradeoffs) is when values appropriate for one scope of optimization get directly applied to another, when egoism or coersion target your circle of concern, or altruism gets turned back on yourself (or enemies). Or when the boundaries get redrawn in a strange way (someone with a lot of power could consider quite a lot of other people “theirs”, applying egoism, optimizing for effectiveness without respect for autonomy).