Burraq is a mount from Jannah. It was brought to the Holy Prophet (Sallallahu alaihi wa sallam). Instead of this, it could have been that the distance was shortened for the Holy Prophet (Sallallahu alaihi wa sallam), the earth could have been rolled up for Him, so that one step of the Holy Prophet (Sallallahu alaihi wa sallam) could have been in Makkah and the next in Masjid Aqsa. This was not done. This is because all this is common in the Auliya (saints), but a mount which completes the journey in the blinking of an eye is the distinction of the Prophets.
Another reason is that the Burraq was not brought because it was needed, but it was to grace the Burraq and to express the grandeur of the Holy Prophet (Sallallahu alaihi wa sallam).
When the elite of this world are invited, a mode of conveyance is also sent to them. This is to respect and revere the person. Similarly, Allah Ta'ala sent such a mount for His beloved Prophet (Sallallahu alaihi wa sallam) that no human had ever rode one like it.
Allah Ta'ala could have sent any of the usual mounts of Arabia and made it fast like the Burraq, or any conveyance from the future could also have been sent, but it was not so. This is to show that the way the Holy Prophet (Sallallahu alaihi wa sallam) is incomparable, His mount also should be such that before Him no one had rode one and after Him no one ever will.
If any vehicle from the future had been sent, then in the later times, people would have used such vehicles. For this reason, Allah Ta'ala sent a mount from Jannah, on which no one else from the world can travel.