> how is that different from the way VCs / investment funds work in general (taking fees from the LPs in exchange for their services)?

VCs usually raise a fund, i.e. a basket of commitments from LPs, before finding the investments. That means they negotiate the investment terms from a position of strength, commitments in hand.

With tenders, the investor starts by commiting to the issuer and then finds LPs. To the degree they have leverage, it's in their access to the issuer.

For the former, the fees are in exchange for risk. For the latter, they're for access.