Yes, 7 ft wide trailers are much easier to tow... The typical full size pickup is 80" wide - less than 7'!
On most highways it's not an issue... They're 12' wide lanes, but rural roads can be legally as little as 9' per lane. Meeting another trailer or commercial truck (which is typically 8' wide leaves only 2' between if you have an 8' wide trailer... Trying to run your trailer on that outer edge of the road will eventually result in running off the edge. May result in tire damage, loss of control, etc.
I'm an experienced CDL class A driver... I don't like narrow roads and wide vehicles! But, I have to drive them anyway - slow down and don't wander out of your lane.
So, get the trailer you want, but, realize an 8' wide trailer is harder to drive and park!