You absolutely don't need the "appearance" of armor. There was an old saying around here back in the day... "the batsuit does not need to appear armored to be armored" - impact hardening plates, nano fabrics, exotic materials, all that sort of stuff. And all that stuff actually exists; just needs a bit of movie fiction to make it work. This approach would have worked even in the Nolanverse, and in the Snyderverse it's a non-issue - if the audience can accept flying aliens, Greek gods, cyborgs, etc., etc., etc., then they will accept that a mega-billionaire has the wherewithal to adapt existing materials to his particular needs.
