Do you understand what a regression line is?
Just draw one through the above graph and see the upward trend.
Problem for your regression is you need to compare to a reference (say developing country average, preferably around the time of same stage of per capita consumption as BD is now) to make sense of the time elapse. Which you conveniently have not done (and you will not do because BD will come out terrible). Not to mention the pitiful base effect in play for BD. Anything under 5 billion USD per year is a big failure for BD at this level of backwardness and flat growth given the huge catch up needed. Considering all of that BD certainly is stagnant in FDI (quality, directed investment).
India for example (about 10 years ago) when it was at the current level of consumption per capita as BD, was raking in 25 billion USD per year and the growth in the time frame you picked for BD was around 20% a year. BD on per capita scale would either be needing around 4 billion a year (if it were growing at that rate) but much higher level if its growing at its current FDI rate in your time frame (around 12% a year - augmented to large degree by extremely low base). In fact this is not even taking into account the lower quality of smaller FDI chunks in absolute level generally so its even worse.
India in last 3 years went from 25 billion to 45 billion a year. Bangladesh in same time period went from 1.7 billion to 2 billion.
And what is wrong with loans if they come on good terms? Japanese charge just 0.1% interest and a grace period of 10 years and the loan is payable over 40 years. ADB and World Bank loans are also very good. Russian and Chinese loans are ok but not like taking high interest IMF loans.
Loans are routed through govt. If you dont understand why thats a major problem in BD case, hah ok. Just watch the fun. We all know where BD govt is institutionally rated and what the corruption metrics are.
FDI on other hand is routed through private enterprise. It is qualitatively on another scale....given it has to be profit bearing and thus tied to mechanisms operating a lot better than those found in a sub 10% corruption percentile (in world rankings) govt.
BD is by far the least indebted country in the whole of S Asia with debt/gdp ratio at only 27% of GDP. India is at 70% by comparison.
No one really cares what a bad junk rating debt/gdp ratio country has, that too one within the GDDS structure of IMF. Are the countries worse off (yes a few exist) than Bangladesh doing better because of their even smaller debt/GDP ratio?
It basically is the ceiling/proxy on offer by the world debt market given the circumstances of the country. Who knows what the BD debt/GDP would be if it had a non-junk credit rating? It would depend on the mercantile/consumer development ratio and many other factors, but its all hypothetical because the current reality is something else all together.
India has 3 times less debt/GDP than Japan and plenty of other richer countries. So your non-existent seignioriage, LDC quota dependent country is a tiny rice grain in this conversation to being with. If you want to enter that convo, turn investment grade first for at least a decade, then we will talk. Till then its a case of getting cut off from options, rather than you consciously forgoing it.