Is $22/hr a good MERN developer rate?

Yes, when it comes from a senior in-house offshore team with NDA, IP transfer, and a replacement clause from a registered company. $22/hr from a reputable agency like Acquaint Softtech is 70 to 75% cheaper than a comparable US MERN developer at $80 to $100/hr. $22/hr from an unvetted freelancer platform is a different product, with no continuity, IP protection, or replacement guarantee. The rate only represents good value with the operational protections included.