Many "old guys" always disparage new cartridges as doing nothing that "tried and true" cartridges don't already do. What they don't get is that most cartridge development in the past century has NOT been to increase velocity.
Most basic smokeless-powder calibers and velocities were established by 1917. Most of what's been done for the past 100 years is tweaking case-shapes to produce the same ballistics so cartridges will work in different actions.
This is because actions varied considerably over the first few decades of smokeless powder, when many were weeded out. They still continue to be refined, and the increasing popularity of AR's is a perfect example. But much cartridge development during the last half of the 20th century was due to the appearance of the Remington 722 in the late 1940's, which fixed "short" bolt-action magazine length at a little over 2.8 inches.
Then came the high-BC bullet trend, due to affordable, civilian laser range-finders, which appeared in the 1990's. This made too many of the established "short" cartridge a little too long for the now-established short-magazine length.
No, muzzle velocities and bullet diameters haven't really changed much in the last century. But rifle actions have. Not every action is made to accommodate the .30-06 or .375 H&H anymore, or even the .308 Winchester. If you prefer using such actions, and cartridges and bullets to fit them, by all means do so. There are plenty around.
But not everybody wants to, the reason there are no laws against case-shape tweakings to accommodate 21st-century realities in rifle actions or bullet shape. You may consider these "fads," but millions of other shooters don't.
I remember a time, a whole decade ago, when many Campfire experts were questioning the reasons for the 6.5 Creedmoor, predicting it would fall flat on its face because "it doesn't do anything the 6.5x55 or .260 don't do." If the only reality in rifle cartridges was muzzle velocity, then they would have been absolutely right. But it isn't, which is why the 6.5 Creedmoor is well on its way to becoming a standard chambering.
So get over it.
