I fully understand your question, and ask myself that on occasion.
We have gone over 5,800 miles on the Great Loop over the last year encountering a vast array of conditions. I will say that this entire trip could have been done with much lower power than the Cummins 380 turbo. Having said that, there were a number of situations where I was more confident and perhaps safer because of it.
We cruised in some uncertain weather windows knowing we could speed up if necessary to reduce risk. We also found ourselves in narrow ocean inlets and also in windy cross current marina fairways where the extra power kept us out of trouble. And of course there were a couple of times where we sped up to arrive at a lock opening or bridge sooner.
The larger engine was not the reason I bought the America Tug. I bought it because I liked the size, layout and especially the quality of materials, equipment and construction. I bought it because it had low draft, low bridge clearance, pilot house doors for ease of docking and anchoring, a galley up, a walkaround queen, a fully enclosed shower, etc. I bought it because I thought it was the perfect boat to do the Great Loop. And importantly, I bought it because my wife liked it.
This engine is just what the manufacturer puts in this boat, so I get the advantages/disadvantages of that decision. It was not even on my list of "must haves". Would I buy a SD hulled boat with an "high performance" engine again? Yes. But I wouldn't let the lack of it keep me from buying the boat I overall liked best.