I see nothing wrong with a wood frame. You can always reinvent the wheel and make it run longer.
This is what aluminum construction does, great for people putting on a lot of miles.
Wood has been around for a long time, as long as you buy a quality built wood trailer you will be fine.
You want a build with straps and screws. Nothing that is completely staples.
There is a lot of brands, coachman, Cherokee ext.
Aluminum siding does get hail damage easy, so consider your location and weather.
On the plus, wood will not sweat in extream hot and cold.
On the down, check seals often and resell often.
Hope this helps, consider all your options, pick what is right for you and your budget.