Well, there are a few other factors you may want to take into account:
1) EPF board has some industry/union, non-governmental representatives to hopefully provide some additional oversight. TH has none.
2) The EPF Act guarantees the contributor's principal as well as a 2.5% dividend per annum. So the government can always print more ringgit to give you back your nominal investment. (yes I know this is not exactly the most comforting thing).
3) EPF's actual investment returns are higher than the declared dividend. The balance of the returns are kept as reserves against fluctuations in investment value. Of course the recent MYR devaluation has also helped their foreign investments show leveraged returns in addition to the typical equity appreciation + dividend.
4) EPF has the advantage of being able to invest in the entire universe of investment assets whereas TH is restricted to syariah compliant instruments. Regardless of actual performance/characteristics of syariah compliant assets, this does restrict potential opportunities as well as increase cost of compliance.
5) EPF's liability/asset ratio is much healthier at circa 6% compared to TH's (official) 50%.
6) EPF actually restricts non-salary contribution amounts. Not a typical Ponzi scheme characteristic, you'd think they would encourage more contributions rather than less. Clearly they recognise it's a tough job managing that much cash. They also allow withdrawals once your individual total EPF holdings has exceeded RM 1mil
At the end of the day you will always have imperfect information as an outsider. But there's not a lot you can do about it...... I do know someone who uses EPF as a government guaranteed fixed deposit replacement.