Is cardio necessary to add in to your lifting routine for lean mass gaining and losing BF?

I have some recommending to hit the weights on Mon, Wed and Fri, then Tues, Thurs go for cardio / HIIT exercises.

And yet i read some say cardio and HIIT is not neccesary as lifting is enough exercise already.

Any sifu can clear this doubt?

Does it mean that if you stick to a clean diet + weight training, cardio or HIIT exercises can totally be out of your weekly routine?