=DATEDIF(A2,B2,"y")&" years "&DATEDIF(A2,B2,"ym")&" months "&DATEDIF(A2,B2,"md")&" days"
=LET(startdate,A3,enddate,B3,DATEDIF(startdate,enddate,"y")&" years "&DATEDIF(startdate,enddate,"ym")&" months "&DATEDIF(startdate,enddate,"md")&" days")
=LAMBDA(startdate,enddate,DATEDIF(startdate,enddate,"y")&" years "&DATEDIF(startdate,enddate,"ym")&" months "&DATEDIF(startdate,enddate,"md")&" days")(A4,B4)