Yes — a warm and cheerful countenance is a genuine act of worship, not a trivial nicety. The Prophet (ﷺ) said, "Do not belittle any good deed, even meeting your brother with a cheerful face." He also said, "Your smiling in the face of your brother is charity (sadaqah)." A believer therefore greets others with an open, pleasant demeanor, spreading ease and love while gaining reward for it.
Evidence — the daleel
Sahih Muslim 2626 ṢaḥīḥJami` at-Tirmidhi 1956
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.