I feel like snake boots are a little bit of a gimmick. I've owned them and they're nice, but has anyone ever heard of a snake actually biting through regular rubber boots?
Snake boots are unquestionably "marketed" by preying on our fears. But they aren't a "gimmick" either. Should a big rattler or cottonmouth strike your foot or lower leg, rubber boots may not protect you; snake boots will.
An averaged sized rattler's fangs can penetrate your rubber boots (and/or neoprene) like it's just a layer of butter. So can a big cottonmouth.
Fortunately, the most aggressive (and generally most common) viper is our Copperhead, which has short fangs & the least potent venom. You would normally be ok wearing rubber boots in protecting against their bites.
Even though I do more my turkey hunting in areas with big rattlers, the snake I fear most is the cottonmouth. They can be as or more aggressive as copperheads, but cottonmouths have long fangs and a venom that's almost as potent as the rattlesnake.
I've had some close calls, have stepped on all three, and only the stepped on rattler didn't strike. A large copperhead hit me above the boots, somehow got is fangs hung in my jeans, but there was no bite on my leg.
Fortunately, I was wearing snake boots when a large cottonmouth hit me right above the ankle. I have no doubt he would have got some venom in me if I'd been wearing rubber boots. Have also had several unprovoked copperheads & cottonmouths strike short or miss, but have never had a rattler strike at me (unprovoked).
Rattlers will more commonly just get out of your way, and/or not strike you when you step close, but you can't count on that. And it they get their fangs in you, it can certainly kill you.
That said, more people die annually from bee & wasp stings. I hate wasps worse than snakes, and fear ticks more than wasps.