Ask any business if money, locked up in a warehouse, buildings, machines, etc... is not a cost factor.
If you calculate, for any business, the discounted cash flow, then any "frozen" money during a time is discounted as a cost equal to the interest you pay on that amount of money during that time.

If you are going to claim that you make a profit, because you've locked up 10 million dollars during a year in material, and you got a return of 200 dollars over what you spent, I wonder how many people are going to consider that *you* are still in touch with reality

And if you think that a savings account has zero real interest, you should change bank.  Because a bank uses your money you put on a savings account to lend it to people wanting to get a loan.
It is true, however, that these days, real interest rates are so terribly low (because low demand, and high offer) that you hardly distinguish nominal rate and inflation.  But on a savings account, you're supposed to get more than just the inflation.

And finally, I already explained that caveat.