By having 24/4 access to others, we seem to be drifting into a society where messages and connecting via social media is almost more important than actually spending time together in person. We care more about how our relationships look than how we feel about the other person.
That’s not to say that you shouldn’t have “low maintenance” relationships, where you can meet up once a month and barely speak otherwise, but even then there's a level of respect where you wouldn’t want to flake on them. However, when you have a relationship where you see the other person too often, perhaps cancelling last minute is just that, and not “flaking”.
There's a level of respect where you wouldn't want to flake on your friends...
I think that flaking has become far too socially acceptable; it's to the point where there are some people who you’ll make plans with and instantly know that it’s not going to happen. Now, this isn’t too big of a deal if you’re in a group, and know that it’s not going to too negatively effect the plans. However, if the plan was just the two of you, then how long are you willing to wait around for it to happen?
Realistically, if you know someone will almost definitely flake on you then you’re not going to want to continue that friendship, so why do people keep flaking if they know it will impact their relationships in the future? Perhaps it’s an unwillingness to put themselves in a different situation - maybe anxiety plays a role - but in the end, it just comes down to people's priorities. If they are not willing to prioritise you and your relationship or friendship, then it’s time to re-evaluate your situation.