Why is CCSD(T)/aug-cc-pVTZ not a suitable method for the geometry optimisation of omeprazole?
To transform the question into something simpler, let's assume CISD instead CCSD(T), which is cheaper and share the common expensive step.

The molecule has 182 electrons and 1545 basis functions in the basis you specified, that means approx. 1400 virtual orbitals.

Therefore, the number of double excitation $ij \rightarrow ab$ is approximately $180 \cdot 180 \cdot 1400 \cdot 1400 = 32400 \cdot 1960000 = 63504\cdot10^6$

Unfortunately, in each of this excitation you have to calculate integral of type $(ab|cd)$, and there are $1400^4$ of them.

Such a big problem is out of reach for traditional CCSD, but tractable with more approximate methods.