The Biden admin. has freed five innocent Americans. The freedom and well-being of US citizens are paramount to this administration and are worth the high price. Besides, though Republicans may try to spin this as the US giving Iran "free money," the unfrozen funds are from legally undertaken oil sales, so the US taxpayer is by no means footing the bill. Also, the US is putting additional sanctions on Tehran regarding the killing of Mahsa Amini.
This "deal" is nothing more than a reward for terrorism. The Iranian regime is one of the most rogue regimes in the world, and Biden just gave Tehran billions in funds that they can now use to threaten US forces and allies in the region. On top of all of this, Biden is enabling Iran to build a nuclear weapon through his misguided diplomacy, which would change the geopolitical fabric of the entire region forever.
There's a 70% chance that Iran will possess a nuclear weapon before 2041, according to the Metaculus prediction community.