You shouldn’t worry about whether your investments are making a social impact or not. There’s nothing wrong with buying a broad market, low fee index fund and using a portion of the profits to directly help the causes you care about.
A lot of these “impact” funds are little more than narrowly tailored funds that charge unduly high fees to pad the fund manager’s income just so people like you can feel better about where your money is being invested. I wouldn’t quite say it’s a scam, but it’s something within the same ballpark.
There’s this one dude where I live who inherited a bunch of KO stock from his parents and uses the investment income to singlehandedly keep a failing homeless shelter afloat. Calls himself the Coca-Cola Anarchist. Personally, I’d rather see the homeless shelter shut down (it’s a CDC recognized hotspot for drug resistant tuberculosis), but the dude is putting his ill gotten gains to an ostensibly noble cause.