When all of the electricity they use in both production and use is renewably generated they will be. Until then they are merely competing and not winning over ICE.
Or realise that on wind-free days wind turbines don't generate and that solar can be patchy and don't feel inclined to shell out on a solution no better in green terms that ICE (on days where renewably generated electricity is scarce, recharging an EV is wholly worse than ICE. Will EV drivers refrain from recharging on such days?). That, and other drawbacks mainly related to recharging - which may be a figment of imagination for some but for others are insurmountable obstacles. There are good reasons why a person may not want an EV and it isn't necessarily the case that the person is wrong in their conclusion. No amount of persuasion will change that. The EV, its green-ness of sourced electricity for recharging, and the recharging infrastructure has to adapt to user's demands.