Why it takes almost 10 seconds to pin a CID?

I’m running a series of ipfs pin add bafy... commands one at a time on my local node. The files/CID were uploaded to nft.storage prior. I noticed that each pinning takes from 5 to 10 secs. But yesterday, around 1am PST it was a lot faster like 3 secs for each.

Has this got to do with overall traffic, meaning less people using IPFS the faster it gets? If so, does the traffic here refer to nft.storage or IPFS in general?