OP hasn't told us which carrier, where he bought the ticket or the fare basis. It all matters.

I am just guessing that he's talking about a discounted domestic US ticket on one of the legacy carriers. Those often carry a $200 penalty to cancel or change. The balance or the whole thing subject to a change fee later is available for OP's use for another ticket within a year.

As to OP's first question, it is OP who chose to buy the non-refundable ticket and then change it. If he needs to do that a lot, maybe it would be cheaper to buy refundable/changeable tickets. Can't answer that without specifics. But, to be blunt, it is OP who agreed to the $200 fee. Not much to complain about after.

Carriers overbook flights and take into account noshows. They are already counting on some number of OP's out there and don't really care if he calls in or not.

Finally, it sounds to me as though OP hasn't read the fare rules carefully. He may not understand that at least some of those tickets which he failed to cancel had some value left over and that he could be using that value on new tickets.