That's sort of true but also a very simplistic way of thinking. There are many things that folks can do with $36k that will outperform current interest rates on a new car loan so that cost is usually offset anyway. There are no guaranteed returns in investing but paying cash for the full amount guarantees 100% of the risk of owning a sinking ship is on the buyer. Financing it puts some or all of the risk on the lender while I still have the cash and flexibility I otherwise would not have.
There are times you will get a better deal not paying cash as the captive or dealer will count on making their profit through borrowing costs and other incentives at signing which will net you a better deal OTD. In that case, finance, lease, take the incentives and do what is necessary to come out on top.
There are some who prefer to pay cash and not worry about payments and that's okay too if it works for their situation as not having a payment has its own benefits.
Regardless of how the car is financed, it is always important to negotiate a cash (OTD price) whether it is a cash, finance, or lease deal (cap). That is always the starting point then figure out interest/MF, terms, etc. Once you start negotiating backwards based on financing (payments) it gets complicated and you will for sure get bent over or stretched.