Why we cannot brute force Elliptic Curve private key?
The creator of the key pair can do it efficiently because he has to calculate $kG$ for only one value of $k$. The cost would be something like $\log(k)$ elliptic curve operations. It's very small.

What you propose is to compute $1G$, $2G$, until you reach $kG$. Since $k$ is a big number (something like $2^{256}$, it is very big), then you have to do $2^{256}$ times more operations than the creator. It is very big.