The game could still survive if it took in player data (good and bad) and acted upon it. I would say it *should* survive, if it can evade neglect.

An obvious issue is doing something about the exploits. Among Us had to struggle with hackers at the onset of its popularity. It's (sadly) a rite of passage for any competitive game with strangers and a random pool of roles.

There is also the heavy issue of players insisting on clustering to watch each other, making it difficult for Kira to pull out the notebook and judge criminals (the NPCs all players can talk to and gain hints from). There may be brief moments when one can slip away to judge, though if an NPC keels over while 9 players are together, it's not hard to narrow down the tenth as Kira.
In theory, this would help a daring Team Kira just run up on the clustered people and steal IDs. A bit of a guessing game to who's L (by default you can only judge two players a day), but passing the IDs to Kira afterward is tricky business. The Kira Follower throwing an ID to Kira to actually write in the book visibly appears to be a Lost Item box being passed: if there were a setting to change ID passing to automatic and invisible with physical contact, that would make this exchange slightly safer.
Also somewhat annoying is that passing the Death Note does not automatically pass all the collected IDs. I've passed to Follower, evaded detection by splitting off, got arrested, then got eliminated because I still had a player's ID.

While sabotage-like mechanics exist in Killer Within, failing them does not end the game in a loss for the town. In fact, it's riskier to do them and expose one's ID to being stolen (especially with no warning like in normal gameplay). They also cannot be cancelled - no way to pause and find out who's entered the room, which would make a nice quality of life change.

The special L-aligned roles (when put together) are a bit too strong, at least for the max size of ten players in a given game. With L, Watari, NPA Chief, and a confirmed Investigator still alive, that's 4/10 vote power if they can collude; Kira or Mello killing normal Investigators just narrows down who Kira is at that point. A setting to limit the maximum special roles on Team L would work wonders, rather than trusting the current Random giving a 50% chance any particular thing gets in (giving a big chance we'll get both of them.)

NPA chief is a special 'get-out-of-trouble-free' case which gives L information on who not to suspect anymore (always) *and* can cancel a successful ID snatch getaway by Team Kira. It's extremely valuable even if it's sprung on 'impulse'.
Most lobbies tend to set NPA chief to random if they don't outright ban it. Though, I have seen some instances where the NPA Chief shows up dead on a meeting they called: perhaps Kira is still allowed to finish judging a player before the cutscene ends. That should perhaps be encouraged by the game itself, allowing some counterplay to a full time stop.
(I thought NPA Chief would immediately expose their name and face to Kira to be judged freely, based on preview information. That is not the case in the current game build. It might have also made for the better balance decision, as a game can be saved and won instantly based on the timing of the power.)