Ozymandias
Expert
45-70 Gov is perfect brown bear medicine, very well proven for that task time and again. It remains to this day the go to for most guides in bear country, so that is an inaccurate statement. It is also a great one shot stopper for troublesome feral swine. But, there are a plethora of cartridges that have equal value in this application. But hunting in the thick brush/swamps of Florida provides its own set of unique challenges and cartridge selection is vital in this.
Reliability: I've employed AKs that were badly damaged from explosions and they "worked"! I've had ARs fail me while at NRA matches. I have my favorites just like anyone else but accuracy will hands down go to the AR. The Russians are still employing the 7.62x39mm in many SOF like units, definitely not on a wide scale ... but not abandoned by any stretch.
1) your relying on a niche use case to say the .45-70 is still well-used. It isnt. No military uses it, and 90% of shooters (conservative guess) have never used it, not even recreationally. Its practically no longer used.
2) as you yourself said, many other far better rounds exist to hunt hog
3) AKs are more prone to jams in almost every environment, its “bomb proof” reliability is from its loose tolerances, which also make it prone to fouling.
4) you yourself said that 7.62 is limited standard. It isn’t because its a great round, its because the russians never were able to successfully liquidate their stocks of AKMs to replace with 74s.