Absolutely!
But I just wouldn't take a single reaction to a single meal or food as 'gospel'.
I can get some really different readings for the same food, in the same portion sizes, depending on stuff like whether it was eaten early or late in the day (insulin resistance can vary during the day), the amount of stress and activity I have before and after... and so on.
As an example, I know perfectly well that a meal of pub burger and chips is going to affect my bg significantly. Probably spike me to 12+ on a normal day.
Not something I would eat regularly, although I have been known to do so.
I usually stick to extremely low (or no) carbs.
About 18 months ago we went on holiday and took a long, fairly strenuous walk along the Northumbrian coast, including exploring a castle, the tower, and clambering about. Significntly more exercise than usually fits into my sedentary(ish) life.

By the end of the walk, my legs had reached the wobbly stage, and my husband was carrying one of the dogs (haha!)
My bg normally runs in the 5s and 6s, but partway through that trek it dropped like a stone down into the low 4s and stayed there (presumably due to exercise induced reduced insulin resistance).
We ended up trundling cheerfully into a pub and I ate an ENORMOUS burger and chips. Delicious.
And my bg hardly shifted. I think it rose to the early 5s and stayed there for a while.
The next day, everything was back to normal, insulin resistance had bobbed back up like a cork, and I DIDN'T eat another burger and chips.
So yes, individual readings are always useful to know.
But they don't always add to your overall management. Better to do a few tests on a particular food or meal, in typical circumstances, and see what the general trend is.
I would love my 'typical circumstances' to include daily coastal walks and pub meals, but sadly I have a desk job, a fairly sedentary life, and my daily exercise is a dog walk at lunchtime on local streets or local parks. On the flat. With pauses for dog sniffs and chats to aquaintances.