They just chuck in a few more bearings and thinner plastic for the body and a quick paint job to catch the eye .Modern reels are vastly better machined than old ones but the basic designs the same ,it's a device to store line and catch the eye of the gullible neophiliast nothing more (ok I googled) .
Bearing overkill is a moot point I have had many tangles where you set up a rod and put it on its rest with the handle 'just so ' and the damn thing is so loose its handle insists in moving by itself spoiling my day .I am the boss if I want my handle horizontal it's damn well going to stay where I bloody want it multi step anti reverses help (about the only good invention along with bait runners since the 50's) but that's not the point .
Luckily my pocket decides what's bought not the lust for the new fashion that rarely lasts 6 months before something with an 'X' or two or an agressive name like beast master or ripper on the label crops up to tempt the foolish .If it ain't broke it's fine imho
Thinking about it what HAS changed there's been a few fads like line going through the rod and closed face reels but technically all that's changed isn't design but materials that have. But graphite rods are just an refinement of fiber glass not some tech that's changed tackle since the 50's or before. You could even say an intrepid elite was a bait runner it allows line to be taken with the spool closed but then if you loosened the clutch they all do .All inventors have done is turn a line holding drum 90 degrees with the means to put the line on it for storage and release ,basically my old turn spool spool alvey is it's dad .