ISSUE:

Hello, as I have been looking at the resonant form of the enolate it attacks through carbon, but I wonder if it is not possible that it attacked through oxygen to form esters for example?

If it doesn't happen why is it usually?

Is it simply because the resonant form is more present as a carbonanion rather than an oxoanion? Regards!

Hellooooo!
That's right, enolates can attack through both oxygen and carbon, it depends on the type of electrophile and in the case of formation of cycles of its size. In reactions such as alkylation, aldol, Michael, the enolates attack through carbon, since it is more nucleophilic, compared to silicon reagents they do so with oxygen, due to the great affinity between these elements.
In cyclization reactions, if the cycle formed by attacking with oxygen is more favorable (five or six members), it will cycle faster than carbon.

I send you a greeting!!!

Thank you so much!! have a good weekend!