First let me say that I am not a builder! I built this 2' x 6' bench in 2016 when I was insulating my shop and I wanted it to be solid because I was mounting a huge vice on the corner and I didn't want the bench to ever move. I didn't take as many pics as I thought but here are a few as I was building it. What can't be seen is the Steel I used in the left corner to tie it all together and mount the vice, the 2x4's you see in the last pic each supported over 250lbs just as you see them, they were bolted and nailed in place. Also you will notice that it looks wonky because the garage is on a pitched concrete pad and the bench is level tied in to a bench I built years ago on the right side which is also bolted in place.
Glenn