Why may Social Class be not Relevant anymore in Modern Terms?

-21st Century has had Class and Partisan Dealignment, along with Issue-based Voting [Brexit] been the Dominant Force. -2017 GE saw DE split between Conservatives [43%] and Labour [47%] -2019 GE saw Conservatives get Support from all Social Classes - AB to DE -Therefore Class is not as important as there is no Clear cut Division between how the Classes vote