You can't say generally that failure is costly. Tons and tons of failures cost nothing at all. Failures are inherent to learning. You can't generalize about the cost of failures, it totally depends on the type of failing.
Now, if you read the word as a state of being as in "being a failure" then you missed the entire point. The fixed mindset of seeing yourself in your identity as "a failure" or "a success" is stupid and should be discouraged. Failing is a verb, it's something you do or don't do in all sorts of cases all the time. It would be better to never think any of it is about "being a failure" in some personal identity way.
Be it measured in raw materials, labor, time or "merely" money, most failures cost. In fact I've yet to hear of a fallible endeavor that can fail without first expending at least some portion of the investment required for success. (And if it requires no investment, I've no idea how it is supposed to produce anything.)
Sure, that makes sense. The point is that if the only cost is the cost of the attempt itself, then it depends on that detail. The cost of me posting this is some time and energy. By bothering to post, I continue practicing communication skills and open myself to learning new perspectives from others. If all that succeeds, maybe it's worth it (although maybe I have more valuable things I should be doing).
If I fail to have a productive exchange, then the cost of time and energy is indeed non-zero. But I will have a good chance of learning something about where I went wrong (because I have a habit of reflecting on things and learning what I can from each little exchange), so it's not a total loss.
But I'll accept I was wrong to imply that there's absolutely no cost to some failures, that was too strong a wording. I'd count that as a minor failure in my efforts to communicate with nuance. I'll keep working to improve. Cheers
Now, if you read the word as a state of being as in "being a failure" then you missed the entire point. The fixed mindset of seeing yourself in your identity as "a failure" or "a success" is stupid and should be discouraged. Failing is a verb, it's something you do or don't do in all sorts of cases all the time. It would be better to never think any of it is about "being a failure" in some personal identity way.