Great weapon master 2024

Hi, Great weapon master (general feat) PHB 2024 Lv 4+ strength 13+. You gain ...: +1 strength.... Heavy weapon mastery. When you hit a creature with a weapon that has the Heavy property as part of the attack action on your turn, you can cause the weapon to deal extra damage to the target. The extra damage equals your proficiency bonus...

If I take for example a warrior lv 20 any subclass ( without skill) with greataxe +5 strength.

If I m not wrong : 1 attack + 3 extra attacks = 4 attacks.

So I m not wrong: Maximum: 4D12 +4x5 + 4x 6 ( B. Proficiency) = 48+ 20 + 24= 92 per turn. Minimum: 4+20 + 24 = 48.

It s colossal. I ll have only 2 handed warrior at my table

What do you think?