Yep, I'm picking up that you're sceptical about most things, and you definitely have a hate of milk cartons
Parallel hybrid
assistance drives such as the BMW system posted above by
@DenisM and the
Toyota 48v hybrid system are principally a bridging technology to help current ICE maintain compliance with strict exhaust emissions and fuel consumption targets via Euro 6.d and Euro 7 just around the corner.
48v tech also provides 'mild' improvements to acceleration and throttle response from standstill without burning more fuel to get the same gain. For the stop/start nay-sayers Toyota use the 48v motor to get the vehicle rolling then restart the engine like a rolling push start in a manual transmission vehicle. Toyota claim this makes the stop-start system smoother and it reduces starter motor operations.
Your asked: Does it achieve anything? It's extending the life of current ICE technologies and anyone who likes ICE should be thankful for that. It's no free ride though. Hybrid tech comes with cost and weight penalties and creates packaging challenges when slipstreamed into existing platform architecture; e.g. where to hide the 48v lithium battery and associated systems? I'm looking at you 7 seat LC 250 Prado (I mean, WTF Toyota?)
We should expect the next round of B58 and B57 powered Grenadiers and Quartermasters to have a 48v mild hybrid system. This was indicated by Justin Hocevar (APAC Head of Ineos Automotive) at an owners event in Brisbane earlier this year.