I think Spain would like to get rid of it but I doubt very much that they can, all EU countries must provide one for their citizens. .
There were cases reported last summer of Spanish hospitals/clinics refusing to accept the EHIC card which led to the European Commission launching legal action against the Spanish government, citing "hundreds" of cases in which foreign holidaymakers needing urgent medical care have been let down. I have not read the results of this action anywhere.

I wouldn't travel with just the EHIC alone I always have additional insurance , it's just not worth the risk.

Obviously you can only use them at their 'national health' facilities ie not private hospitals, clinics or Doctors, and it does have to be for emergency treatment. If they don't deem to be an emergency you will be asked to pay.
I have one, but have never used it. If I ever need emergency treatment I use my insurance and go private.

As Judith says, always have comprehensive travel insurance as well.