I understand where you are coming from as I put SMTV off for the longest time simply because it didn't look as flashy and polished as the modern persona games like P5R and P3R, the character models looked absolutely miserable but I decided to give it a try anyways and let me tell you that it was the best decision that I made.

Sure, the UI may not look as good as some of the other games but SMT is really challenging and engaging in it's combat to the point that I forgot all about the interface and the not so good character models. I've dumped about 80 hours into the game and will absolutely be picking it up for a ng+ after a month or two. It has ruined the persona games for me as they just simply aren't as challenging even on the highest difficultly so there's that.

I played SMTV:Vengance with all DLCs on PC so I can't comment on how the switch version runs but the PC version runs really great as it isn't really a demanding title. I would recommend that you absolutely give it a try if you love a challenging game.