Speakers have gotten a lot better but at some point you’re fighting physics. If you want to move a lot of air, you need mass and volume. Most of our modern systems using a fairly similar formula to speakers from the 1960s, but we have better materials and amplifiers. For example, you can use a neodymium magnet but this isn’t really a revolution in speaker technology, it just means you can make a smaller/lighter speaker.
That said, speakers have gotten a lot better since the Dynaco A-25 came out. They cost $160 for a pair in 1969, or about $1,100 in 2020 by the CPI. You can buy a pretty damn good system for $1,100.
Almost everything else has gotten better, or at least a lot cheaper and less trouble for comparable quality. But speakers haven't.
Mind you a lot of that old stuff was crap too.