It's very easy to identify people who know absolutely nothing about tractors.
They're always the ones who say, "you gotta have a 4wd".
For the most part, a 4wd tractor will do nothing that a regular tractor won't. It does come in handy with a loader, if equipped with the right transmission. But it'll make no difference pulling most implementation or almost anything else a farm tractor is used for.
So you don't believe two tractors , same HP , same weight, same rear rubber, only difference is one is 2WD and other is 4WD that the 4WD will pull best? Also explain what difference the trans makes when doing loader work with a 4x4.
In most cases, it won't make any difference because the bulk of the weight and torque is on the rear-end. Any additional traction gained from a live front end is mainly noticeable in added steering control, rather than pulling power. On muddy ground, with a 4wd,you might not have to use the brakes to assist with steering as much as you would with a 2wd. But I can get the same job done every time with a 2wd tractor.
With regard to transmission, if you have a standard manual shift, you're just as likely to burn up a clutch, using a front end loader, with a 4wd or 2wd.
The 4wd does have an advantage when equipped with a shuttle shift or similar transmission.
The obvious downside of the 4wd (aside from added cost and maintenance) is rapid wear of the front tires, especially if you have to put them on the pavement very often.
