It does seem loyalty to an airline would decline if not rewarded. Recent changes reduce the reward and likely undermine loyalty. But how much do carriers care

It does seem loyalty to an airline would decline if not rewarded. Recent changes reduce the reward and likely undermine loyalty. But how much do carriers care at this point? Two factors likely contribute to policy decisions of the airlines. Mergers produce less competition, and secondly, it's quite noticeable over the last couple of years that every flight is packed full. Consequently, a shortage of seats assures carrier income which makes loyalty much less relevant, in particular loyalty that's tightly linked to miles traveled. OTOH loyalty programs connected to credit cards are probably more profitable to airlines, and in today's world more effective in maintaining loyalty too.