I agree. If I write my own framework which only does what the app needs it does a lot less and can easily be refactored if need be. Usually it isn't a framework at all, just some shared functions. I don't like have tons of unused functionality shipping with my app.
With maintenance the same - if your app is really small most time will be spend upgrading framework (and adapting app in case of deprecation of an old API or other incompatible changes). And you cannot just stick with an old framework version because there are security fixes (and the bigger framework the more often they happen).
But for medium sized app which is actively developed framework can be quite useful.