asthma damages lungs?

I just read that untreated asthma damages lungs in the long term.  Is this true?  I thought asthma affected the small airways, not the lungs themselves.  This person said that it can cause scarring of the lungs that in later years can cause the quality of breathing to be so restricted that it can't even be controlled any longer, that the most these people can hope for is to make it 'liveable'.

First, I can't imagine anyone with asthma not wanting to treat it.  Why would anyone choose not being able to breathe over using something that will make this possible?  So I guess I don't understand 'when' asthma would be left untreated, or why someone would.

Also, my asthma is so mild that I don't need to use anything to control it, either a rescue inhaler or a controller.  99% of the time I am fine, the other 1% I may feel a very slight tightening that is barely noticeable and certainly doesn't affect my daily living.  By after reading this, I'm so upset that I can't help thinking that, What, in 20 years I won't be able to breathe because I don't use an inhaler now??

I would very much appreciate someone who's an expert to explain this to me, as I'm sure many others would also be concerned if they read that.  Thanks so much.

[National Jewish]

An example of when asthma would be left untreated is a person who is having symptoms, but they have not yet been diagnosed and started on treatment.  Some people do not realize when they are having very slight asthma symptoms, so their symptoms go untreated.  Other people don