Lived & owned homes for 20 years in an area where ASHP are standard installs as the climate range meant 100% of normal (outside of freak polar vortex) heating and cooling was covered by the heat pump. Inexpensive part failure is common annually - usually capacitors and fan motors. Usually expensive part or system failures occur around 10-15 years.
The moving parts are identical to an air conditioner. Those go for decades reliably.
We had 2 in our office closet datacenter and they definitely needed more maintenance than what I remember our coal burning furnace did