One of the reasons why governments are not accepting Bitcoin is that governments cannot control Bitcoin. The way governments usually control everything related to the country's finances through their central banks will never be possible with Bitcoin. Moreover, due to Bitcoin being extremely volatile, governments have not been able to gain full confidence in investing in it. Lack of education about Bitcoin is another reason why governments are not yet interested in Bitcoin adoption, but those who are gaining knowledge about Bitcoin are researching how to make Bitcoin usable in all area. The governments of many countries have started investing in Bitcoin. They have launched educational programs about Bitcoin in their countries so that they can quickly gain good knowledge about Bitcoin and develop further in the world economically.
I do not think they lack knowledge or do not understand it. Bitcoin is not too difficult to understand, and even ordinary people like us do not need much time to grasp it. Meanwhile, the government has no shortage of resources to study it, they understand it better than any investor. Do not underestimate them, it is simply because they can not control it, and thats why they haven't accepted bitcoin yet.
Furthermore, volatility is a barrier that makes them hesitant to add it to national reserves. Because what the government need is a stable asset to protect the economy, not speculative asset.