Bitcoin adoption is still at an experimental level, so it is difficult to say whether it will benefit the national or world economy. Furthermore, when bitcoin is only used as a speculative asset (what's going on) it can't really generate any national interest. We need more time for bitcoin adoption to become more popular, more people to adopt it in real life, then we will see how impactful it is. It is too early to say that bitcoin is benefiting and improving the world economy, but it is also impossible to conclude that it will never bring any benefit.
No data yet showing that it help improve the economy since country like El Salvador seems struggling since bitcoin is really unpredictable in terms of its movement. But once they experience all scenarios for sure that country can see some change on its financial system or maybe the economy might get a good boost if there's good events will occur in the market. For now lets see how their adoption go and if they fail or succeed with this action they do.