Are the gifts and the power of the Holy Spirit prevalent today? Yeah...but I think they've waned significantly to where the power is only displayed through a relative few, and definitely not through the majority of believers. I don't think it's so much akin to "a switch flipped" (display vs. cessation) as it is akin to "fuel in the tank".
One element often used to represent Holy Spirit in scripture is oil.
In Zechariah 4, he's given a vision of two olive trees with branches connected by pipes feeding the oil to the lampstand in the middle, and we're told that "This [image] is the Word of Yah to Zerubbabel saying, 'not by strength nor by power but by my Spirit'" and then it talks about how The Almighty's temple will be built.
Next, when we read the beginning of Revelation we're given an image of the Messiah standing in the midst of 7 lampstands that we're told represent the seven churches. "Let your light shine before men..."
Heading back to the gospels, recall the parable of the wise and foolish virgins that were all waiting for the groom to arrive. Five were considered foolish because they didn't keep oil in their lamps...and when they tried to borrow some from the wise they were denied because then the wise wouldn't have enough to keep burning their lamps as they waited.
If we put all of this together, knowing what happened at Pentecost, I think we can conclude that when the "oil" was initially distributed to the body of believers the church's light burned brightly at the beginning (i.e. dynamic displays of the power of God through believers to the nations)...but as these past 2000 some odd years have gone by the "oil" has started running low as the church has become more and more worldly and less studied in the Word of Truth; its light dimming as a result (recall the prophesied "falling away" that must occur).
So fewer and fewer believers are actually able to display the power of the Holy Spirit through certain gifts (i.e. healing the sick, raising the dead, casting out demons, speaking in other languages, etc.), while other corrupt shepherds deceive the rest through artificial displays and other nonsense.
What we need is another distribution of oil. The second tree is needed to complete Zechariah's prophetic vision for us today. We need a second outpouring of Holy Spirit.