A double axle trailer has plenty of benefits of its own. The big one of course is size. Generally double axle trailers will be larger and be able to accommodate larger loads than a single axle trailer.
A double axle trailer will be more sturdy on the road and while you are loading. Given it has more stability it can be easier to load and unload safely. This is especially true when hauling bigger loads and when you have less hands to help. On the road a double axle trailer is also going to be more stable. Due to this you are less likely to develop trailer sway and the trailer is less likely to slide on loose surfaces. Double axle trailers will also move less on corrugated roads. If stability and sturdiness are going to be important to you, the double axle trailer will be a better choice. Another little bonus is that when you get a flat tyre is will be a lot easier to change.
The two biggest negatives for getting a double axle trailer is the cost and the size. Due to the bigger size and more complicated construction double axle trailers are going to come a premium. The upfront cost of a double axle trailer can be worth it as they are more reliable and will most likely last longer into the future. The size of double axle trailer can be a blessing and a curse. It is great when you want to move those larger loads. It is not great when you need to work in confined spaces and manoeuvre around smaller roads and driveways.