It'll never be literally indispensible, because open models exist - either served by third-party providers, or even ran locally in a homelab setup. A nice thing that's arguably unique about the latter is that you can trade scale for latency - you get to run much larger models on the same hardware if they can chug on the answer overnight (with offload to fast SSD for bulk storage of parameters and activations) instead of just answering on the spot. Large providers don't want to do this, because keeping your query's activations around is just too expensive when scaled to many users.