If the government takes money (either through taxation or inflation) from you and spends it at will, creating malinvestments, what value did it produce? Negative value, meaning that if it didn't take money from individuals, they would use it in a way that would provide actual value to them (measured by the price system).
Look, of course you can insist on using a definition of value that is 100% tied to price by definition, but that's rather myopic -- and why are you using the word "value" in the first place then? You should just be using the word "price" instead, because that's what you mean.
The vast majority of use of the term "value" by people in practice attempts to capture some essence that goes beyond market price. For many goods, market price can be a decent approximation of this more elusive notion of value, but that's all it is: an approximation. Or a (leaky!) abstraction, if you prefer to think of it that way.
Heck, even in finance, it's not as simple as "value = price". For example, when analyzing firms you can look at market value vs. book value. Both can be thought of as "the value of the firm", but they're basically always different.
On your comment about market value and book value, both are measured in monetary terms.
The thing here is that we can't come up with an abstract definition for prices and values where anything goes and then use it to justify something economically unsound such as the government activity.
That's precisely what has been happening periodically since we started having governments and states (around 8000-10000 years ago).
One way to measure the value of a government is to estimate how much people would voluntarily pay for the government services if they were not forced through taxation and inflation. As governments are highly inefficient and bloated, most likely nobody would pay the services they provide, and would prefer more efficient free market alternatives if they had a choice.
Now, governments still have to give something back in order to avoid an instant revolt. Modern governments do that through debt spending, meaning: they make the future generations pay (through debt) for the "economic growth" that the current generation enjoys.