I read this the other day, too. While I wasn't surprised that they make more off of other parts of their business, I was surprised to see that amps are only 5% of their sales. Pretty stunning initially, but if you think about it, it makes perfect sense. There's a TON of used Marshalls out there. They've been making them for 60 years. The prices of new ones have skyrocketed since 2019, so they probably aren't selling a ton of new ones. Couple that with the fact that Marshall is the worst innovator of their own sound (literally why Dave Friedman made a million dollars), and you have a recipe for selling headphones, refrigerators, and speakers.
That said, they do have a point. It is true that Marshall is synonymous with rock and roll attitude. Think about it. People have seen huge Marshall stacks behind guitarists for 60 years. People go somewhere, see a Marshall stack and go, "Oh yeah, this is going to be a rock and roll band." So when it comes time to buy a Bluetooth speaker, if you love rock and roll, then a Marshall speaker is probably appealing to you.
One last thing. It is kind of sad that this is what Marshall has come to. As I said above, Marshall "clones" and "takes on M-style sounds" are better than anything Marshall is putting out today. I guarantee Dave Friedman's Plex amp will wipe the floor with a stock 1987X. That is simply so sad. Marshall probably only sells 5% amps because they absolutely refuse to innovate. Instead, they leave that to guys like Friedman, Bogner, Headfirst, etc. It's just a brutal late chapter to an otherwise amazing rock and roll story.