I'm building a little side business with LLMs doing 90%+ of the work, and this includes numerical analysis of revenue to figure out where to direct effort.

Today the problem you're mentioning is easily avoided if you are aware by ensuring you direct the agents to build tools for anything deterministic.

Every week "we" (myself and Claude) start by analysing revenue from the previous week. Claude will do some manual proposals but they will be based on analysis done by a deterministic script. It will then run workflows that are increasingly calling deterministic scripts - every week another few decision points the agent used to do (and that I had to then manually vet) gets replaced by deterministic scripts.

It is what allows what is a very low margin opportunity to work - it is scaling with the total amount of manual labour and total token use remaining near constant. It's an opportunity that I won't go into much detail about because the margins are thin and the moat narrow and it's basically only viable because of this approach of setting a tiny budget where ~1/3 of it or so is dedicated to systematically eliminating manual and LLM work from the process.

Even so, I expect the opportunity to actually extract profit from it is going to be short-lived - the moat will eventually evaporate if LLMs keep getting cheaper and better in favour of people "just" asking an LLM to do the whole thing end to end.

So on one hand I agree with you - there are lots of things that'd be better automated with scripts, and where there might well always continue to be efficiencies you can extract by turning things into deterministic scripts instead. On the other hand, LLMs are already so cheap for a lot of things that it increasingly doesn't matter, and good enough that where it does matter they will increasingly also just write tools themselves if you ask them and sometimes - and likely increasingly so over time - without even being asked.