Article could do with some explanation of latency (delay) vs. bandwidth (units of data transmitted per time unit).
Effectively the whole article is talking about latency (mentioned exactly 1x). But sometimes high latency might be okay if subsequent events occur at a high rate (your "truckload full of SSDs" arriving after being stuck in traffic). Which is how many internal busses, IC-IC protocols, or longer-distance serial connections work.
Yeah it does mention parallelism - 2 trucks can carry more SSDs than 1 truck. Duh..
What's commonly called "speed" or "performance" is a combined (mixed) effect of the above.