Fedimints add a multi-signature aspect to federated custody. Liquid is a sole federation member (Blockstream) that can rug you, leaving little to no recourse. Fedimints would require, depending on your chosen federation's set up, multiple key holders in the multi-signature model to collude to rug all users (including the other key holders), resulting in reputational damage, public ridicule and in some cases physical harm.

The best analogy in fiat world I can think of is the choice between a bank and a credit union. Banks have shareholders outside the institution that influence decisions made within the bank procedures. Credit unions are a bit more personal. You normally need to know someone in the CU to become a member and then the reputation of the credit union is based on how they serve the members, not some arbitrary shareholders (the members ARE the shareholders). It comes down to a social contract, where those who will choose to use fedimints will choose mints where they either know one or multiple of the federation key holders, or they live close enough to them where they can go exact revenge if a rug pull occurs (as NVK likes to call this: Proof of Punch).

The benefit to most who trade-off this collaborative custody model will be privacy, via UTXO obfuscation (once the sats go in the mint, they can be pooled and sent out with little to no fee to the user of the mint). In this scenario, you do not have to trust a single mixing coordinator, since most ecash tokens will be interchangeable between mints.

I am by no means a fedimint expert, but like most things in bitcoin, tradeoffs are in the eye of the coin-holder.