It does not say: Sarah obeyed, you should obey. It say Sarah obeyed, and you are her daughters if you do well, and are not afraid. The wording is:
1Pe 3:1 Likewise, ye wives, be in subjection to your own husbands; ….
:3 Whose adorning let it not be that outward adorning of plaiting the hair, and of wearing of gold, or of putting on of apparel; 4 But let it be the hidden man of the heart, in that which is not corruptible, even the ornament of a meek and quiet spirit, which is in the sight of God of great price. :5 For after this manner in the old time the holy women also, who trusted in God, adorned themselves, being in subjection unto their own husbands :6 Even as Sara obeyed Abraham, calling him lord: whose daughters ye are, as long as ye do well, and are not afraid with any amazement.
1 Peter 3 say women should be subject to their husbands (or perhaps that should rather be translated “are subject“?) , and adorn the inward with meekness (recommended for both genders, see Matt. 5:5) and quietness (recommended for both genders, see 1 Ti 2:2) rather than the outward.
They should get an example in how to adorn themselves (inwardly, not outwardly) from the holy women of old. Sarah obeyed Abraham and called him lord/ sir (while he called her princess – female ruler in reality). Wives are daughters of Sarah if they do well, and are not afraid – it does not say “obey like Sarah”.
(By the way, Sarah’s radical obedience came when she had no other options.)
Women (were all women in mind, or particularly those whose heathen husbands was still steeped in Roman patriarchy?) could learn from Sarah.