[null and void]

Under the Old Covenant the nearly impossible task of exactly following some 500 commandments sufficed those observant Jews who through faith and obedience managed it.

The New Covenant opens the door for all, Jew and gentile alike who accept their salvation.

St. Peter came with the New Covenant, and therefor holds the Key of Grace and Redemption.

He also must honor the Old Covenant, else His Word to the ancient Jews would be false, therefor St. Peter holds the Key of the Law as well.

My take, YMMV, as YHWH wills...

[Hebrews 11:6]

Under the Old Covenant the nearly impossible task of exactly following some 500 commandments sufficed those observant Jews who through faith and obedience managed it.

Apparently, friend, and with the greatest respect, you have Missed the Memos from Jesus and Paul: that task is completely impossible:

"There is no one righteous, not even one...
for all have sinned and fall short of the glory of God"
Romans 3:10, 23