you raised a very interesting question.

At no point in time did God's standard of holiness change.

The mosaic law was meant to show mankind it is simply impossible to humanly meet God's standard of holiness all the time.

That set the stage for the requirement of a Savior.

Jesus Himself said

“Do not think that I came to do away with or undo the Law [of Moses] or the [writings of the] Prophets; I did not come to destroy but to fulfill. For I assure you and most solemnly say to you, until heaven and earth pass away, not the smallest letter or stroke [of the pen] will pass from the Law until all things [which it foreshadows] are accomplished. So whoever breaks one of the least [important] of these commandments, and teaches others to do the same, will be called least [important] in the kingdom of heaven; but whoever practices and teaches them, he will be called great in the kingdom of heaven. “For I say to you that unless your righteousness (uprightness, moral essence) is more than that of the scribes and Pharisees, you will never enter the kingdom of heaven.
Matthew 5:17‭-‬20 AMP
https://bible.com/bible/1588/mat.5.17-20.AMP

So when Jesus hung on the cross, He uttered "it is finished" or in greek "telelestai" which is a word when used in business, means the debt is fully paid, in law, it means the sentence is fully served and if in military, the battle is fully won.

Today, christians worldwide do not follow the moasic code because Jesus has already fulfilled all the requirements of it.

And when we choose to abide in Jesus, we are deemed to have fulfilled the requirements also.

So did God lower His standard of holiness?, no.
God recognise that Jesus has met that citeria and therefore, all who accepts Him as Lord and Savior also meet that citeria through Jesus.