mass can be converted into energy at nearly zero cost (via hot fusion, cold fusion, LENR, etc.)
*In theory*. In practice, those technologies don’t quite work yet, and it’s not 100% clear that they will ever be efficient enough to use for most practical purposes, which is not “nearly zero cost”. There’s certainly hope that one day they will be, but regardless, it’s not something which we could use as an immediate fix for energy issues.
Energy, in turn, can be used to create fuels and fertilizer,
If by “fuels” you mean for farming equipment and food transportation, why would you use energy to create fuel to convert back into energy? There are some specialized applications where this is the best option, but in general it’s highly inefficient. Also the current trend of turning hydrocarbons into fertilizer is unsustainable, so we need to work on better options. Unless you’re talking about phosphorus, in which case presently we need to work on recovering or retaining existing phosphorus so that it doesn’t mostly end up in the ocean, rather than mining for more or converting silicon to phosphorus via fusion or whatever idiocy you’re thinking of, because that’s not really viable or sustainable either.
The rest of this is just wishful thinking that we can burn through all of the planet’s resources and it will all naturally get recycled or replaced - which it will, just not on timescales which would allow future generations to continue maintaining civilization. And also thinking that the only thing preventing us from doing so is purposeful corruption and mismanagement intended to keep the population down… corruption and mismanagement are certainly issues, but with maybe very rare exceptions are lacking any malign purpose beyond short-term greed and power, and have less overall effect than technological and logistical bottlenecks. (Political complications count as “logistical bottlenecks” for most practical purposes.)