The arguments go back & forth.
You get full use of the truck bed with a TT. True, but the 5er has all of that storage below & it is covered out of the weather.
The TT has fewer steps. True but my 5er has built in excercise steps. Execise is needed.
The TT is easier to back into tight spots. Very true, but with the help of a good DW spotter, a couple of radios & some determination a 5er can be shoehorned into some tight to get into sites.
For dry camping a 5er is more likely to have a much larger water tank & room for more battery capacity.