I agree that there's a difference, but it's not mutual exclusive.
Opening credit cards doesn't necessarily hurt your credit, usually only by a few points. And I don't close cards that I open; I downgrade them. The key to open new credit cards is a bonus that's actually worth it: don't open a new cc with a $50-$200 bonus. Get the ones that give you 80,000 and up points. Usually those points if you have a Chase Sapphire Reserve are worth 1.5, so that's $1,200 worth of points. So if you want to stretch your dollars during retirement, that's the way to go.