It’s the typical Catholic shorthand of tradition (says the old lady).
When we look at the Cross, we associate Christ on it, even when the Cross is being carried ‘empty’. In fact, some Protestants accuse us of "Keeping Christ on the cross’ instead of showing an empty cross because, "He isn’t there anymore’.
But when we look at the sacred (holy) wood of the Cross (which is sacred/holy because it carried His Blessed Body upon it), we are worshiping the Christ who offered Himself on that cross.
NOT worshiping the cross itself as a god. The cross is worthy of respect (worth-ship, the quality of being worthy), but latria, the quality of worth-ship, worthiness, and worship due to God alone, is so much more.
Thing is, our world gives so little respect and acknowledgment of worth to those things which have worth–including the unborn, the elderly, the ill, etc., that giving respect to a sacred OBJECT is so ‘strange’ an idea to many that they just can’t wrap their heads around it. What, respect a CROSS? Respect a ‘fetus’? Respect some 'old person" that’s just 'useless"? respect a ‘baby’ that ‘does nothing?’ respect a WOMAN? Respect some 'dumb man?" Etc. etc. No wonder we keep narrowing down and narrowing down and having less and less to offer God, ultimately.
We need to ‘open up’ and broaden and rediscover the ‘sacred’ so that we can open up, broaden, and give more glory to God by giving glory to what He has sanctified and made holy.