A well implemented system would somehow allow you to use your ID to prove you have the attributes a service needs (being over 18, able to drive, no criminal records, not a communist or whatever it is they need) without providing any further information that would allow multiple services to correlate ID's against eachother.
>>weavie+(OP)
Making confirmations of those attributes easily available will only result in more services requiring them. It's not worth the convenience for the vanishingly few cases where such a verification is actually beneficial.