This is not true. Iran may not have the biggest bitcoin adoption but it definitely is not as low as you think. The statistics you quoted is also worthless.
Just to put the adoption into perspective you should know two things. First is that Iran has been experiencing a big inflation over the past couple of years. In simple terms bitcoin's price in IRR when it dumped to the absolute bottom of $3100 in 2018 was the same price in IRR back in 2017 when it was $8400. In other words when if it dropped from $8400 in 2017 to $3100 in 2018 its price remained the same in IRR.
Here is some big numbers:
2017-12: $20000 =   820,000,000 IRR
2020-12: $20000 = 5,440,000,000 IRR
To be fair the price in 2020 coincides with dollar price bubble which would burst in a month and price drops 35% but still you can see the inflation and how bitcoin has been providing an excellent option against the inflation for Iranians.

Second is the sanctions. Iran has been under sanctions for more than 40 years and during most of it Iranian banking system has been cut off from the rest of the world. So when an Iranian wants to make an online payment (like buying a game from Steam) they can't. Bitcoin solved this issue easily since it can not be censored or sanctioned!