Say you decide to grab a coffee from a coffee shop. You need to cross a busy street for that. If the coffee costs $5, and the chance of you getting killed by crossing the street is 1 in 100 000, then by getting that coffee you demonstrate you value your life at less than $500 000 --- value of life * probability of death < cost of coffee.
Of course I make risk assessments but they have nothing to do with money. You might try to measure the value of my life in dollars by measuring my risk assessments, but because I'm irrational and human you won't get very far I don't think, and besides, dollar value doesn't really correlate well with actual value anyway.
I'm not arguing that you're running this calculation in your head, nor that any of us makes rational risk assessments. My point is that every such assessment implied by doing anything implicitly establishes a dollar value for life, that this value is always finite and must be so, and that you can learn something from looking at them in aggregate.
Doesn't this only work if there's consensus on these dollar values? So first of all, weird anarchists like me are a lost cause, because we refuse to participate in measuring human lives in dollars. You might then argue that's fine, normal people like yourself will continue to measure things in dollars, however I'd point out, that even normal people like yourself fail to achieve consensus on dollar values for things like risks, lives, etc. From where I stand, it all looks very arbitrary, and completely detached from any kind of reality.
For example, real estate. Many would say the market finds the "real value" of a house. It's so expensive right now, because we don't have that many houses to live in. Right? Yet rent is rising higher against salaries year on year: https://ipropertymanagement.com/research/average-rent-by-yea... despite vacancies seeming to never move below 4% and above 7% https://en.macromicro.me/charts/22864/us-house-vacancy . And now we find out some of the reasons for that are collusion among landlords and agencies: https://www.propublica.org/article/yieldstar-rent-increase-r... (reported on as early as 2022).
So if you normal folks can't even decide on the value of the house (or stock, or NFT, or pokemon card), or can simply manipulate this value, why should it be believed when you claim to have figured out the value of a human life? Especially because none of these measurements take into considerations things that actually matter for humans, e.g., that housing is necessary for a reasonably comfortable life and should simply be guaranteed in a society this wealthy?
There's not a single global dollar value for a life; a value can be established in context of some specific things, and then there is consensus pretty much by definition.
The whole point here is to make safety measures comparable to other important expenses. You can't say whether they're more or less important without a common base of comparison, and you can't run the budget assuming a life has infinite value, because then you'll have zero funds for anything. So, when you do a consideration like: a marginal extra bollard costs $10k, and saves one life per year, how many more bollards should we fund from our finite budget, where this money would otherwise go to fund schools or social programs? If you say "all of them", then you won't have schools.
That same life may have different value when different tradeoffs are considered, e.g. when discussing automotive safety (see the infamous case of recalls), or ordering evacuation of a city (you need to compare lives saved from a probable calamity vs. total destruction of local economy), etc.
And on a more general point, there is no single fixed thing as "monetary value" of a thing. The price is always a consensus of market forces, a measurement of a dynamic system. The value of your house may be $4M if you're selling now, or $1M if you want to sell it right right now, or just $0 if you literally can't find a buyer for it. Fixed price is an illusion.