system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Are electric motors nowadays vastly more efficient than an electric motor from 100 years ago?

I've disassembled electric motors from about the 1950's, and they seem identical to the ones we have today.   So have there been any advances in electric motor technology in the past 100 years?

I realize that things have become smaller and more streamlined, and permanent magnets have become more powerful, but these seem like simply incremental changes.  

The only thing I can think of is brushless motors, but beyond that has anything else substantial changed?
gpt
Electric motors pretty much maxed out on efficiency when they were first created, we have motors today that can hit 99% efficiency, but that doesn't give you the right picture

A motor that you just want spun up to a constant speed can be made very efficient and you just connect it straight to power and you've got yourself a highly efficient motor.

But what if you want to control the speed?  Well now you need a motor controller and this is where most of the efficiency gains have been had.  Advances in switching electronics allow us to feed the motor exactly what we need to and only draw what is needed from the batteries, earlier systems would generally have to throw a lot of the unneeded power away as heat which isn't efficient and drains your battery.

So while motors have remained around the same efficiency as components, the systems involving motors have increased in efficiency as we could build motor controllers with fewer losses.