Latex condoms, when used consistently and correctly, are highly effective in preventing the sexual transmission of HIV, the virus that causes AIDS. In addition, consistent and correct use of latex condoms reduces the risk of other sexually transmitted diseases (STDs), including diseases transmitted by genital secretions, and to a lesser degree, genital ulcer diseases. Condom use may reduce the risk for genital human papillomavirus (HPV) infection and HPV-associated diseases, e.g., genital warts and cervical cancer.
Your belief may be that condom effectiveness is better than 80% but that doesnt mean your belief is correct. More like burring your head in the sand. If you have nothing to back up your comment then it is not really very meaningful.
Ignore the bit... "This would imply 1 session of unprotected sex carries about the same risk of HIV infection as 5 sessions of protected sex." ...as I'd meant to delete it as its not correct.