It won’t be. The games industry is littered with hardware that flopped. Most indie games fail to turn a profit and even the likes of Sega and Nintendo have released hardware that has failed to sell. Apple couldn’t even make a successful console and they had tried. Yet this thing is weirder and significantly less appealing to the mainstream so they’re reliant entirely only a super niche crowd to turn a profit.
While I’m sure they will sell some devices and they will likely become a collectors item in the future; I can’t see them selling enough to make this worthwhile nor keep people playing on it long enough to be considered anything more than an expensive yet short-lived novelty item.
Hopefully I’m wrong, but as a collector of games consoles - including many of those that failed - I’m not filled with any confidence about the Playdate.