Everyone keeps talking about this "last coin mined" thing like it is something that is close. First of all the last coin that will be mined is estimated to be at around year 2140, I know there has been some calculation difference and we are on a faster track but if we keep this up going for a long period of time it still won't be anytime soon.
Hence you do not have to worry about the last coin that will be mined. Even with that in mind, like it was previously mentioned the last coin that will be mined is not the important part here because the transaction fee's cover the expenses already hence the mined coin count is not important anymore. People are mining and making money thanks to the transaction fee's already and the longer we wait the more people will start sending and receiving money hence the transaction fee's will be more in number.