It's all down to suitability of purpose,if you look at the names of the lines you will see ,super soft,super tuff,high vis,low vis,long casting etc. it all depends what you want a line to do,ie. a stillwater waggler angler will want a line that sinks,whereas a stickfloat angler (if there are any left) will want it to float,most top anglers use two entirely different lines I.E. mainline and hooklength,with different properties such as durability and low stretch for mainline,also floating or sinking,then hooklength needs to be supple and stretchy,low visibility and low flash,then there is rod action (or pole ) to take into consideration,also the angler himself some are hamfisted lol.there are so many variables it is totaly unfair just to judge a line by breaking strain versus diameter,everybody finds a line that best suits their needs eventually.
