Abraham is mentioned at the end of the surah because he is mentioned in context of hajj in previous verses. What did he do for us to be told to follow ‘his’ creed?
There were rites given to previous generations but now the Quran has come so we must only follow this.
22:67 We have let every community hold some rites that they observe (as diversity in humanity 49:13). So, let them not involve you in their arguments, just call them to your Lord (2:177). You (O Prophet) are on the right way.
22:68 And if they argue with you, say, “God is best Aware of what you do.”
22:69 God will judge among you regarding all your differences when humanity stands up on its feet, and finally on the Day of Resurrection.” [2:213, 22:17, 22:56]
22:70 Do you not know that God is fully Aware of all that is in the High and the Low? All that is in the Divine Database. Surely, all this is easy for God.
22:71 AND YET, THEY (SEEING HIS DOMINION OF THE UNIVERSE, AND CLAIMING TO BELIEVE IN HIM) IDOLIZE INSTEAD OF GOD THAT WHEREIN HE HAS PLACED NO POWER, AND THEY KNOW NOTHING ABOUT THEM. BUT THERE IS NO HELPER FOR THOSE WHO RELEGATE THE TRUTH. [THEY BLINDLY FOLLOW THEIR ANCESTORS 10:39]
The above is a clear statement that confirms other verses about Abraham that we and him cannot follow anything other than God.
22:72 AND WHEN OUR MESSAGES ARE CONVEYED TO THEM IN ALL CLARITY, YOU CAN NOTICE A DENIAL ON THE FACES OF THOSE WHO ARE BENT UPON REJECTING THE TRUTH. THEY WOULD ALMOST ATTACK THOSE WHO CONVEY OUR MESSAGES TO THEM. SAY, “SHALL I, THEN, TELL YOU SOMETHING WORSE THAN WHAT YOU FEEL NOW? THE FIRE! GOD HAS PROMISED IT FOR THOSE WHO ARE BENT UPON OPPOSING THE TRUTH. HOW MISERABLE A JOURNEY’S END!”
22:73 "O People! Here is a parable set forth. Listen to it! Those on whom you call besides God, cannot create even a fly, even if they all got together to do so. And if the fly snatches away anything from them, they will not be able to recover from it. Feeble is the seeker and the sought.”
22:74 They do not esteem God as He must be esteemed. God is most Powerful, Almighty. [6:91-92, 39:67]
22:75 God chooses message-bearers from among the angels as well as from among mankind. Indeed, God is Hearer, All-Seeing. [Angels being message-bearers = Angels of revelation to the Prophets]
22:76 He knows all that is of the past, the present and the future. For, to God all things return (and go back to Him as their Source).
22:77 O You who have chosen to be graced with belief! Bow before the commands of your Lord in full submission and serve Him alone. And do good to the society so that you may prosper. [Rukoo’ (Bowing) and Sajdah (Prostration) are not confined to the ritual physical motions. They convey a more sublime message of being humble and submitting to God’s commands]
22:78 Strive for God with a strife befitting Him, for He has elected you and placed no hardship in Religion, the Creed of your father Abraham. He has named you Muslimeen in the bygone days and now in this revelation, that the Messenger may be a witness against you and you may be witnesses against mankind! So, establish the Divine System and set up the Just Economic Order, and hold fast unto God. He is your Patron; how excellent a Patron and how excellent a Helper! [2:143. Muslimeen = Muslims = Submitters = Those who submit to God alone = Upholders of peace. 2:132, 2:136]
You may argue over what salat and zakt mean, but you have to use the Quran to tell you what this is, not your ancestors.