Doesnt put no extra wear on engine,all your doing is fine tuning the original map
Basics to start with,every ecu map has been programmed to take into account several factors,firstly not everybody services there car at the correct times,so the ecu has to be set up to account for this,i.e dirty airfilter reduces flow into engine,etc,fuel quality etc,so the manufactures design a map,so the car will still run and keep going,a remap then overwrites this,safety protocols can be reduced,i.e rev limiter,fuel settings etc,this allows the engine to run better than from the factory,and this helps with fuel economy and how the engine runs.
Put it another way,people dont like andriod software,they jail break it and load a custom system which is far better and improves the phone,still same phone but improved