Regarding drugs, yes it´s most likely still happening, but nowhere near the levels it used to be. Riders are tested a lot and have to provide year-round whereabouts for random testing. They also have a frequently updated blood passport to detect sudden changes in values caused by PEDs. It can never be fully waterproof, but at least serious efforts are made.
They have moved on from pharmaceutical doping due to the extensive testing to what is referred to as "mechanical doping". Motors are hidden in hubs/frames and the organisation is busy doing everything they can to pretend that it isn't a problem.
https://www.uci.org/pressrelease/uci-reveals-technological-f...