The steppes of Central Asia was never truly a powerbase in terms of population in Islamic periods or before. It was an area from which nomadic states wielding cavalry and fierce warriors often mercenaries attacked and invaded more populous regions such as Afghanistan and Wazirastan and later India and Iran. It's height was at three consecutive periods where it's power was bear solely derived from its areas.
1. The famous Kwarzemshahs. This state, born from a Mamluk rebellion and takeover became famed for its buildup of Urgench and other like cities in the steppe. It also flourished as a major center is islamic intellectualism and wealth in a time where the greatest Islamic population centers where in ruins or engulfed in wars with Europe, thus making it illuminated amongst the masses. It also, like all other steppe states before it, sought better land, thus the Kwarzemshah-Abbasid wars and skirmishes which the Kwarezmians lost. As well, their proximity to the Qhara Qhitan made their position all too dangerous for a truly great empire. Their time would come against the Mongol hordes emboldened by the absorption of the Qhara Qhitan and Naiman. Their empire fell like a house of cards due to its location and positioning.
2. Ilkhanate/Chagatayid periods. Perhaps the most underestimated intellectual period in Islamic history. The great cities of the steppe where rebuilt as homes of the Genghisid. The steppe benefited more than it ever had from Pax Mongolica and developed far beyond its previous limits. Cities like Samarqand, Urgench, Herat, Merv, etc... flourished for a time. However, there were cracks, severe ones. Ilkhabate and it's Mongol neighbors had issues with stability and near constant battle for positions in local areas. These results are a consequence of a massive lack of centralized power where needed and decentralization in the worst. It became a world where roaming generals could garner enough support to overtake anything before them.
3. Timurids. That time of a great general did come with Timur the great, who forged a massive empire surpassing both the Kwarzemshahs and Ilkhans in splendour in his capital of Samarqand. However, the same cracks in rule began to show, as the night of a great warrior fades, So rises the claims of many men of differing views.
Wars would be fought over dominate over the central Asian steppe for years after. The Shaybanid, the rising stars of the time taking Samarqand and expelling Babur Timurid from Khursan led to a spark in the steppe. However, this was dashed as Shah Is'mail of the Safavids defeats Muhammad al-Shaybani, cutting him into pieces at the battle and sending his pasts across the Islamic world. Thus, the steppe becomes even more and more backward over time.
Sultan and khan after khan rise to power only to be defeated by another snuffing out any growth. The ultimate climax of this was the last two unifiers. Nader Shah roughly united the desperate areas of the steppe and like Mahmoud Ghazni before him, led a jihad into Hindustan to gain riches untold. In the same as many before him, he losses his life to excess and jealousy. Thus Ahmad Shah Durrani or the Durran-i-Durrani rose to power and built a huge empire across India and the steppe.
This empire was the visual of what destroyed the steppe, huge decentralized warlord States all barely held together by brutal khans and sultans. No true intellectual society or large and stable urban populations can be created in such a barely held anarchic warlord state as was seen in post 1500s Central Asia.