Do you really believe that people without God [unbelievers] have changed at all? They remain blind and deaf. People with God are growing and changing or they are in delusion. Many people claiming God and His Son today likely are in delusion, but go slow on drawing conclusions unless God is definitely giving you those conclusions.
And I suppose you have evidence according to scripture or from a direct revelation from God that what you say is true... or did your evidence and conclusions come rather from men and the works of men? You say they "fulfilled their need", but what was that need that does not also exist today? Does 40,000 denominations of Christian believers indicate that we are all One with God and His Son?
Can you answer your own question as to what the purpose of tongues was at any given time? The answer is God's answer, and how many of us would tempt God by saying we really know His mind absolutely rather than only believe? Some of us may indeed know as God has spoken to our hearts and minds through the Holy Spirit, but if I or another were to say that that was the source of our understanding who would believe us? Probably many or even most people would disbelieve as they disbelieve God in so many things. So because the majority seems to rail against us, should we forsake God in favor of what is present from men?
And again this knowledge came to you from the scriptures or from God's direct revelation to you or was it perhaps something you heard from men who well studied in the Bible displayed something like a Doctorate in Theology degree?
"False doctrine"? You certainly seem to disagree with it, but what is it that you really know? You lump Pentecostals together as if they were all exactly at the same place in the road and believe me, from my own experience I can tell you that they are not. If you believe these are doctrines of devils, then avoid them and follow God, but go slow on condemning beliefs about you apparently know next to nothing at all... unless God has definitely given you the job to discredit them. If He has you should learn to use the scriptures yourself instead of simply generalizing or citing the conclusions of other men.
And whose record did you read to draw such conclusions about the history of men and of men's churches? If men in any existing churches were in error, perhaps they would have made no accurate records or someone even burned or discredited the records that others did make. Perhaps the lack of a whole lot of written documentation is simply because we are to live by faith rather than by knowledge. God gave us a written record in scripture in which He purposely, I believe, misleads some people. Even the disagreeing denominations have their purpose... The purpose I believe is allow us to get along even with those with whom we sharply disagree. This is Love. This is Charity.
Everyone babbles early in their faith, whether it is in an unknown tongue or in English. Do you condemn natural babies because they babble before they learn to talk?
And I have been in some non-Pentecostal churches that were really dead to the things of God from what I could see or hear. The script anywhere is wrong if the Leader is not the Holy Spirit in people. Saying that some are wrong is probably a great understatement. I would venture to day that probably most churches settings [Catholic, Pentecostal, Baptist, etc.] are wrong, but don't condemn the people and don't presume to know how to pinpoint one reason why they are in error unless you are always right in the things of God. Who is?