People are only truly motivated when they engage in an activity for its own sake or pleasure, without an external incentive. Deming called this intrinsic motivation. and a hobby is an example.
Rewarding people for doing something removes their own innate desire to do it of their own accord. Extrinsic motivation - rewards such as bonuses, promotion, or public commendation - is probably not sustainable for the long term. Withdraw the reward and the motivation disappears. Keep the reward at the same level and motivation drops off. To get the same motivation next time the reward needs to be bigger. People will come to expect a reward every time they do something. Similarly, the threat of severe consequences for not doing something, such as redundancy or demotion, will demotivate people (and help create a fear culture).
Create an environment that promotes intrinsic motivation. A place where people can cooperate, voluntarily rise to challenges, and are free to be creative and can pursue their curiosity to the benefit of the organisation. Create an open environment (and culture) where people are trusted and not managed to death, which provides an enabling context, or ba, where knowledge is created, is openly available and shared freely. Create a social community that fosters relationships among people where everyone is free to speak and speaks equally, and where everyone contributes. You want people to genuinely enjoy what they do, be happy at work and have fun with their colleagues.