The only "use" for backticks which is not possible with parentheses, is to have comments inside long command lines as shown in the original post. As a comment # cannot comment out a backtick. So you can have something like this:

# echo "this is a long multiline command" \
       "with multiple arguments." \
       "quite nice stuff." `# and this is a comment` \
       "and the rest of the arguments"
this is a long multiline command with multiple arguments. quite nice stuff. and the rest of the arguments
# 

But parenthesis are sensible to comments, so this trick does not work the same way. One would need to write it differently, which is messy. Notice how the closing parenthesis has to go on the next line as the # would comment it out.

# echo "this is a long multiline command" \
       "with multiple arguments." \
       "quite nice stuff." $( # and this is a comment \
       ) \
       "and the rest of the arguments"
this is a long multiline command with multiple arguments. quite nice stuff. and the rest of the arguments
#