You're very wrong about that.
There's a really fine documentary about swords called "Reclaiming the Blade" and it deals with not only how swords were employed in actual combat during various periods, but how the technology changed and developed over the centuries.
Pattern welded blades like the tamahagane type were actually used in the west far earlier than in Japan, and the western blades were much more technically advanced. One such sword found in England dates back to about 700-800 AD. This particular blade has six interwoven strains of soft iron inside a hardened steel outer shell rivaling any modern surgical steel - and it's far more complex than the Japanese tamahagame style blade.
Nobody could make such a blade today. And even at the time, it would have taken a rare master six months to a year make a single sword. In battle it would have been pretty much unbreakable and because of its advanced construction would have been lighter and faster than an opponents sword - with superior cutting ability. That technology was lost in Europe about 1200.
Modern swords are a compromise between flexibility and hardness. There is no compromise in an older pattern welded blade. The outer steel is harder and cuts better than any modern steel sword and yet it doesn't shatter because of its soft steel interior.
If you can find Reclaiming the Blade, it's well worth buying if you're a sword enthusiast.