The Bible places a lot of emphasis on apologetic themes, like eyewitness testimony and fulfilled prophecy. It also commands and commends apologetic work, even to the point of saying that apologetics can "greatly help" (Acts 18:27). Yet, many people, even some professing Christians, suggest that apologetics doesn't do much good and even question whether it's ever been instrumental in anybody's conversion.
Two conversion stories that have been receiving a lot of attention lately illustrate how much of a difference apologetics can make. See here and here for a couple of places in David Wood's conversion video in which he mentions the involvement of apologetics in his becoming a Christian. Notice that, in the first clip above, Wood refers to how other Christians he'd met hadn't challenged him on intellectual issues. In other words, not only was intellectual engagement with the Christian he met in jail important, but the failure of other Christians to intellectually interact with him was significant as well, in a negative way.
Similarly, Nabeel Qureshi, writing of his time as a Muslim prior to becoming a Christian, commented:
"What I needed was something that would not let me get away with my biases. I needed something that would mercilessly loop my bad arguments before my eyes, again and again and again, until I could avoid them no longer. I needed a friend, an intelligent, uncompromising, non-Muslim friend who would be willing to challenge me." (Seeking Allah, Finding Jesus [Grand Rapids, Michigan: Zondervan, 2014], 117)
Like Wood, Qureshi refers to how a lot of Christians he met had made his situation worse by failing to provide the intellectual help he needed. For some examples, see here.
Apologetics does help people and does lead to conversions. And people who underestimate apologetics do significant harm.