For me it's not really the time investment so much as it is the general principle <_<
With a bit more prep and maybe reading up on what the second phase is like I'm sure I could beat it, but I don't feel interested at all in playing a game that is deliberately set up to screw you over like that. No save point inside, no leaving, no warning that you'll need a full team, and the final boss is a huge spike in strength compared to the other bosses so even if you clown them you might be borderline on winning legit? Stupid and I have no desire to indulge it ---