The original concept in trading is to buy at low and sell at high, which is what El Salvador is doing now. I do not know what the long-term benefit of holding Bitcoin will be to that country as it is still in its initial days. They are the only country in the world trying to improve their economic condition by holding Bitcoin and declaring it as one of their legal tender. A country's economy function on various factors and becoming completely dependent on Bitcoin might not be a good idea.
Its original concept or trading as short term target buying on lower price and selling later at higher price, difference with El Savador concept in trading as long term target and keep active purchasing bitcoin however on higher or lower price without any planning in the future for selling their bitcoin assets investment although bitcoin raised new higher price.
Seems get stable economy condition I think reason why El Savador not adopt with original concept of trading by buying on lower price and selling after raising at higher price.
I think keep buying dip and always waiting more dip if you have stable financial condition, its not matter how many time bitcoin raise dip price but keep purchase as great opportunity invest in bitcoin at lower price.