Springs are flat but not on the overload springs yet. You’re fine up to 800lbs more payload (formula is a simple 5,600lb GVWR - 4,800lb weight = 800lbs). But if you’re carrying weight on a regular basis, think about adding a leaf or getting a custom set.
And remember Tacoma’s are not work trucks. They are lifestyle trucks. Meant to carry canoes, camping gear, etc. So the springs are catered more towards that than HD work duties. Results in better ride. This is what America wanted, so Toyota dropped the Hilux in US and created the Tacoma.