Speaker Improvement Advance Design Better Upgrade

In your opinion, what have been the major improvements in home audio speaker sound since 1990?
Quality of drivers as well in terms of being able to meet higher tolerance standards for quality, which enables greater efficiency, better sound quality and more quantity out of smaller drivers as well, when called for.

Also major advances in CAD (computer aided design) and various applications that use it that smart engineers leverage and apply as needed.

All in all, major technology advancement in most every aspect, including crossover design accordingly I am fairly certain.
Hyperion Sound uses membranes without suspension (spiderweb) - reducing moving mass and improving linearity. Midrange driver (6.5") uses ferrofluid for suspension.
Surround Less and spider less transducers have been about since the 1920s. I collect restore vintage design construct modern loudspeakers I would say the largest improvement has been in crossover quality and ease of design and tweeters have improved the most. But no free lunch modern design also has its own issues. You get a more similar design since computer programs are limiting. Also what the buyer wants now is also extremely limiting. If I look at whats made today with a eye towards future collectability I think you will find no wee monitor slim multi woofer tower or subwoofer will make the cut.