Yes, people have tried it and it generally works well for home bartending.
Compared to the traditional muddled sugar, bitters, and citrus method, it’s mainly about convenience. It gives a more consistent, pre-balanced flavor, but you lose some of the control and freshness you get from making it from scratch.
The https://www.agedandcharred.com/products/old-fashioned-cocktail-syrup
version of the Old Fashioned approach is essentially designed to simplify the process while keeping the core flavor profile intact.
It doesn’t necessarily “improve” a well-made classic Old Fashioned, but it does make it easier to get a solid, balanced drink every time. It also works fine in smoked variations, though some prefer the traditional build for more customization.