end grain worktop top

[JWD]

aside from it being a huge effort and difficult to flatten, why not? wouldn't it have the same durability benefits of a butcher block?

 

[Beau]

Obvious problem is it will expand and contract along it's length not just it's depth. That could be a lot of movement to contend with on a 3m worktop!

 

[MattRoberts]

You're going to have horizontal movement in both directions all along the length - it will likely never stay flat, and there will probably be joint failure all over the place on a top that big

 

[Brandlin]

The reason a butchers block is made with end grain upwards is because its easier on knife blades. It's then durable because the chopping action isnt severing across the grain.
Flatness doesn't matter to a butcher - there are very few square cow carcasses.
You wont be using a woodwork bench in the same manner, so the very benefits of the butchers block top dont apply to woodworking.