Since I seem to have missed the verse that says that the 'charismata' (including Tongues) will cease with the death of the last Apostle, I will respect the intent of the OP by saving the debate on cessationism for "Babbling against Speaking in Tongues" and just comment here under continuationist assumptions about the topic "Speaking in Tongues: The Need for Caution".
As someone coming to Christianity from being raised Atheist and choosing Nihilism, I can tell you that the "babbling" of tongues is not purposeless. Let me state emphatically that I make this statement as someone who has never exhibited ANY of the charismata. I first encountered 'tongues' at a Catholic Charismatic Fellowship I was ... well, dragged to. It had the same effect on me, a radical unbeliever, that it had on the crowd in Acts 2. It drew my attention and it left me wondering if these people were really talking to God or just needed their Psych meds adjusted. Had I been dragged to a "proper" Baptist or Presbyterian service (or a Catholic Mass), I would have left just as certain that your so-called "god" was just a snipe hunt for an "invisible unicorn" as when I arrived.
I found this verse to be true: [1 Corinthians 14:22 NIV] "Tongues, then, are a sign, not for believers but for unbelievers; prophecy, however, is not for unbelievers but for believers."
I say all of this not to engage in the contuaitionist/cessationist debate, but to lay the groundwork for a personal observation based on decades in a Pentecostal church. The gift of tongues should be outward focused not inward focused. The 90% false manifestation is usually easily identified by the focus of the attention. Any action that seeks to draw all attention to the PERSON and elevate the human being in the eyes of other people ... is not of God. AS my (former Moravian) Pentecostal Pastor is fond of saying ... "God will share His glory with no man". The 10% of the charismata that is more likely to be genuine, will exhibit the character of the Holy Spirit and seek to draw all eyes to Christ, Crucified and Resurrected, and to bring good to others and glory to God. There are no Christian "superstars".