Counterspelled Booming Blade

[KorvinStarmast]

Making a melee attack is not an Action

Incorrect. Making a melee weapon attack takes an action: the Attack Action.

That is the general rule
It is only by exception (two weapon fighting rule for example, Specific over general) that making a melee weapon attack is handled by another rule.

As to: Steel Wind Strike. That is a 5th Level spell, and not appropriate for a discussion about a cantrip.