What you should be looking at is, the Brake Mean Effective Pressure for the engine or any engine you want to find out how much stress a engine is under. This is a calculation that will give you an idea as to the longevity of the engine, a low BMEP means that the engine is under less stress than an engine with a high BMEP.
You can look up the calculation from numerous websites that will even do the calc for you but if ok with math here it is:
BMEP = (Torque x 75.4) / (Displacement x PPR)
I wouldn't stress over the Tech that will be involved with the new Engine, simply because tech is getting improved everyday. Issues will be plastic bits as per any vehicle, you could ask RAM not a Dealer what is the design life of the new Truck.
Every manufacturer designs their product to have an economical life, thats were the cost of maintenance becomes greater than the replacement cost. Just look at BMW or Audi nice cars but you don't see many 15 years old or greater.
As for ICE's they are going to be around for a long time, main issues are Charge time, Battery Life, Plug adaption currently 3 types, the reliability of charge stations and Towing loads. Stellantis has already said it will continue with ICE development for the future.
( Internal Combustion Engine)