Do warmup sets actually matter or could I just stretch well and be alright

[trueg___]

Like I understand the point of having one warmup set what's light and easy then 2 sets where you put your normal weight on or just work up your progressive overload and 3 in total but if I just stretch the muscles I'm going to work that day can't I just have 3 regular sets with weight on?

I feel like it would save time in my sessions and allow me to actually put abit more muscle on quicker by getting a few more reps In than just 2 sets.

Or is it mandatory unless I'm rooting for an injury.