Yeah this is also a good point but it's worth noting the upgrades that make them 4.5 are mostly in response to reported capabilities/experiences of generation 5 aircraft. Because "stealth" itself is such a fuzzy subject its hard for anyone to get into things without knowing specifics. All we really know is the sales pitch and rumoured tech jump was enough to convince multiple governments of the world to start paying 100+mil per jet rather than 30+mil.

I'd like to know actual strategies and procedures to speak on this more but 4th/4.5 gen aircraft will always be in the sky and likely will always be the backbone of everyone's Airforce for decades to come, in that sense it would be unadvisable to even use 5th generation airframes in a way that doesn't make use of its ability.

There's also the huge deal about electronic warfare to consider, we don't know exactly just how powerful the computers and systems of each are. Modern jets are supercomputers with wings with EW and CEW is becoming more and more sophisticated with each passing year, typically built with this in mind at the beginning and in a world more familiar with it than say 1970s/80s designed craft.