Someone I follow on social media travelled to ecuador and mentioned the #1 currency of choice there being precious metals based coins. Apparently people there have a dislike for both paper money and digital currency. They prefer to conduct business transactions in coins.
If that mentality is popular in central american regions. It could explain why el salvador would have difficulty achieving mass adoption with bitcoin.
If el salvador's goal is to promote crypto mass adoption. The best method they could use is to construct geothermal and hydroelectric plants to offer free electricity to residents. A format which residents could then use to mine cryptocurrencies. With minimum wage in el salvador being $240/month for low income bracket earners in the agriculture sector. Any gains made through crypto mining could go a long way towards improving their bottom line. For the approach to be successful, they might also need to subsidize the cost of GPUs and ASICS imported into the country.
As mining difficulty for most coins on a global scale is quite competitive. The next stage would be to deploy their own native coin with a low mining difficulty that was available exclusively to resident in the country. Of course, this is nothing new and has been tried in years past with iceland's auroracoin and similar projects:
https://en.wikipedia.org/wiki/AuroracoinThe basic blueprint and history of best methods for pushing crypto mass adoption has been around for many years and is nothing new.
If I remember right el salvador had also proposed "bitcoin city" which they intended to be like "akon city" and all of the other smart city, wakanda forever, development projects that were trending in news at the time. But the actual goal and motive could have been something other than crypto mass adoption. As can be common in politics.