Yes, mark to market accounting is a good approach to accounting practice, because mark to market is the most fair approach. It is nice to say that something should be worth what it costs to make it, but the truth is that something is worth what someone else will pay for it. This type of accounting values things based on this principle.
Yes mark-to-market accounting is a good accounting practicing, because valuing something according to its current value allows the business to be competitive in the current market. A good is worth what someone will pay for it. It does not matter if a person made a poor choice paying too much for it in the past, or if market conditions have changed, the most accurate value of an object is what someone is currently willing to pay for it. That makes mark-to-market accounting a good practice.