Analyzing the Long-Term Viability of Bitcoin Mining in Light of Halving Events

Is it a fact that the halving event halves Bitcoin miner rewards. I want to know if, at a certain point where the reward becomes so small that it no longer justifies the effort and costs of mining Bitcoin (assuming it still has relatively low value), this could lead to mining becoming extinct, subsequently ending the primary validation mechanism for transactions, and ultimately leading to Bitcoin's demise.