Allow me to help with understanding by way of scriptures and actual exercise of them. I've learned that probably most Christians have had no first hand experience with tongues, as well as most other spiritual gifts designed for congregations to experience in a worship service. As it was for me my Baptist years, it was easy to accept teaching that all that passed away when the last apostle died. Over time I began going past just reading
1 Corinthians 13:8 (KJV) Charity never faileth: but whether there be prophecies, they shall fail; whether there be tongues, they shall cease; whether there be knowledge, it shall vanish away.
It appears we have agreement here that tongues has not ceased, like knowledge hasn't, neither prophecy nor love. All of those are in operation today. The common disagreement now expressed here seems to be around the use of tongues in public without an interpretation. Well, the scriptures require either the tongues speaker pray for understanding then speak that, or let someone else interpret. If there is no interpreter then the pastor ought to gently point that out, moving on to a hymn, sing in tongues from the pulpit, or quite often deliver an interpretation of that too. Eventually he/she will know who has that gift, and those who should not "try it out". Most congregations that use that gift have one or two people that are spiritually mature elders that speak it, and one or two who have the gift of interpretation.
An exception that is scriptural, and that is congregational praise and worship singing. I could not estimate how many times we would be singing a hymn from a book or on a screen, when the Holy Spirit manifested in remarkable ways. I have always been very practical, when preaching, sticking to the Bible with minimum discussion, ready to teach or preach without notice, but I have never exercised the gift of tongues prophesy, but have received the understanding, yet not contribute it. But then came my first of many times to join in with the whole congregation singing in tongues, each person "on their own". The result is always an extended time of worship like at the dedication of Solomon's Temple, but without of course that dramatic entry of God into it. It's very liberating to find your self face down on the carpet, full of unspeakable joy. There is no interpretation possible or necessary. Here's why.
Acts 2:6-8 (KJV)
6 Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language.
7 And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galilaeans?
8 And how hear we every man in our own tongue, wherein we were born?
I believe there might be too much emphasis on the speaking of unknown tongues, that is, the words, the sounds when the major thing is what people hear of that. One speaks in what might sound like mad gibberish, but while that is happening, the Spirit speaks a message directly to a hearer, in whatever language they know. That's what happened at Pentecost. 120 disciples were not all vocalizing the same in unison, words not possibly matching or according to a known language. There were thousands of hearers present (3,000 saved that day), each hearing them speak of the wonderful works of God in their own dialects of their home nations. The miracle was, as I see it, in the hearing. Each hearer had no interpreter but the Holy Spirit. That happened again a few times later with Peter and Paul on a much smaller scale. I note also there is no mention that anyone was offended due to lack of interpretations. Nobody needed that! And I note none of them listening are said to have been Christians yet, having only attended the Jewish feast.
The amazement of that doubtless helped the hearers seek faith to believe, then to ask Peter what they should do. I've seen thousands of people over the past decades do the same upon hearing congregational singing in tongues, which is a beautiful sound like that of harps. Visitors fill the altar area, and eventually everyone is there praising and worshiping. That experiences both edifies each person, but is a sign to the unbelievers that it is time to believe. At home we sing in tongues often, mostly my wife singing to me, each of us edified greatly daily
That's why Paul admonished not to forbid to speak in tongues. The Lord uses that to reach the most stubborn of souls, and that quite suddenly.