Comments in the link raise many valid points, including that their proposed model is unlikely to be sustainable with the 1$/month fee. They claim they get their revenue from securities lending etc, but thats then just a hidden fee. It just sounds too good to really work.
IMO it’s close to a case for the “Due Diligence” thread…
So, as others also mentioned, Finpension going to 0 “forever” would also raise questions regarding sustainability. Time-limited promotions and generally low fees are good enough for me.