Also, accuracy and precision on smaller/cheaper tools. I have a "jobsite table saw", which is a thoroughly budget one by comparison to a big ol' cabinet saw. And being a smaller saw has a lot of problems, but one that stopped being a problem is a rack-and-pinion fence even on fairly cheap (~$300) table saws that provides really, really solid accuracy.
Power Tool KickBack Control (and just safety, were dB warnings big in the 90's? Ergonomic's are improving)
Drill bit/blades/disk composition/tech.
The fact I can (almost) throw out tools that you'd never have seen in a garage in the 90's.
And if we are not children and can talk about such things, they can look good. (Although the 90's tools are now retro and also have an aesthetic)
Track down a power tools catalogue from the 90's
Like computers, every thing was invented before the 80's. But now it's usable and accessible.
And yes, the 80% is probably batteries and cost. But there's a lot in the 20% too.
Going off topic but putting a clear window on stick vacuum cleaners literally gamified vacuuming. What that means for asthma for instance we will see over the years.
Battery adapter's (ie. Milwaukee to Makita) went from 3d printed on ebay to injected moulded over a short period.
The female market has been increasing since the 90/00's and is continuing to increase.