It's surprising how many people think that some of the most popular cartridges of all time are "underrated"
270, 3006, 4570, 30-30, 7x57 etc?
I agree with Hoyt, and Jiffx. I'll pretty regularly recommend the 30-30 as a good gun especially for younger and smaller shooters who want to go after big game. It has that 170 gr. bullet that's just more suitable than anything in .224 or .243, at normal ranges assuming we're actually talking "big game". Pretty regularly, there's a few people who start disagreeing loudly, about limiting someone with an "antique" cartridge. Kind of funny when they start mentioning stuff that is 70, 80, 90 years old as not antique, though.
How many people do you know off hand that have a .275 Rigby in their closet? I'll bet not a pile, but probably a bunch have the 7-08 and think it's way, way better...
.270, and 30-06 have been less popular for a few decades. Everyone started getting the 7mm Remington Mag, then the .300 Win Mag, and then all the short mags... I still think the 30-06 is one of the best balanced cartridges out there, and there is a still an audience for it, but the faster cartridges have stolen it's thunder for a long time. So in that regard, yes, it absolutely is underrated. Should be near the top of the pile, but if I was to guess, there seems to be a lot less people picking up new guns in it. It's funny if you mention the 30-06 as an all arounder, you can almost hear the eyes rolling, but the .308 which is less gun in every way usually gets a big thumbs up. Totally weird. Not a big fan of the .270...
The 45-70 has enjoyed a real resurgence in popularity. But as was mentioned, there are quite a few non ballistically inclined people that figure that the old Government hits a magical wall at just past 100 long paces and then hits the dirt. I'll agree that it's not a laser, but it still is totally underrated.