Dont bring the chazon ish or even the steipler into this. Questions like these are time-sensitive & should be asked of gedolim of our generation. But it certainly makes sense not to l’chatchila look for a girl/guy who is so much younger/older for many reasons, some of which are mentioned above eg maturity gap, shiduch crisis etc.
It doesnt suprise me that many bachurim dont see the problem here at all.
However, if in the individual circumstances someone knows both parties and feels that is a passendig shiduch, then to say they shouldnt ‘red’ it at all and should forget it completely just because of the age gap is also wrong.