Microsoft extended support for 2005 and 2008 R2 version SQL server has already ended by now, do the old versions SQL servers above still need license compliance?
Yes ofcourse, does not supported does not means you can run anything without proper license.
Per core based SQL server license model started for version 2012 servers and after, if 2005/2008 version SQL servers still need license compliance, do we have to use service/CAL based license to cover these old servers?
Server/CAL based license is still their, so you need to use that. Speak to local Microsoft Licensing Specialist.