The Frantz are actually a pretty decent unit. They do a good job of filtering but they are the most basic level of bypass filtration, but if it were a choice of that or nothing, I certainly wouldn't talk someone out of one, The things works well for a long time, then in the late 60's early 70's a handful of racers realized the TP wasn't quite enough, and they started stuffing the frantz housings with kotex to make use of compressed cotton batting for better filtration instead of the TP.( there was a precedent for this, the bypass section of mercedes diesel filters is made of cotton batting , for those who didn't know those bullet proof mercedes diesel engines that last forever have come with a factory 2 stage oil filter for years that consisted of a full flow and a bypass filter all in one drop in cartridge filter, which is the main reason for their longevity) One of those racers was one of the Unser boys( can't remember which one now, it's been a few years) and he's been using synthetics for a long time, even though it had some big oil company name on his hood ( heck, all those guys were running synthetics not made by the sponsors who's logos were all over their cars and uniforms, but the sponsors couldn't care less just so long as they were staying up front and keeping the cameras on them)and he helped develop the first bypass setup for Amsoil which came in a housing that looked like a frantz housing( or a small lubrifiner housing) but consisted of a drop in tp roll shaped cartridge of highly compressed cotton discs that was way more efficient than the TP roll filters. soon after that they went to the spin on filters rated for 2 micron and that will remove particles as small as one micron.
There you have it folks, consumer Bypass 101 in a nutshell.
All this was going on about the time these engines were rolling off the assembly line for the first time.