Lots of launch providers and various 3rd parties have been providing rideshares for a while. e.g. there's the big thosuand pound payload, with an extra rack of cubesats to take advantage of extra fairing capacity.
The starlink satellites are relatively small, but they're still larger than Sputnik for example. ISRO has launched 100+ satellites at a time, although I believe those were mostly cubesats which are an order of magnitude or two smaller than the Starlink sats
Starlink satellites aren't small cubesats, each one weighs approximately 227kg. They can launch 60 on a single F9 because the satellites have flat panel design for maximum stackability and take full advantage of the size of the payload fairing.
By reducing their "function" until they're basically a battery with a radio repeater strapped onto it. Obviously it's a bit more complicated, but there's very little these satellites actually have to _do_.
The Starlink satellites additionally have krypton ion thrusters for stationkeeping as well as to raise their orbits from their 290 km deployment altitude up to the 550 km service altitude.
ion thruster, star trackers, phased array antennas, reaction wheels, torque rods, solar panels... they pretty much do everything every other satellite does.
