This is interesting to me, because Claude has been a net-positive for me. I haven't faced token issues or declining quality. I generally work with Claude as an assistant -- I may have it do planning and have it "one shot" a thing, but it's usually a personal tool or a utility that I want it to write.
For actual code that goes out to production, I generally figure out how I would solve the problem myself (but will use Claude to bounce ideas and approaches -- or as a search engine) and then have Claude do the boring bits.
Recently I had to migrate a rules-engine into an FSM-based engine. I already had my plan and approach. I had Claude do the boring bits while I implemented the engine myself. I find that Claude does best when you give it small, focused, incremental tasks.
I've used agent mode, but I tell it not to go hog wild and to not do anything other than what I have instructed it to do. Also, sometimes I will tell it not to change the code, and to go over its changes with me first, before I tell it that it can make the changes.
I feel the same way as you in general -- I don't trust it to go and just make changes all over the codebase. I've seen it do some really dumb stuff before because it doesn't really understand the context properly.
You can't get away from the engineering part of software engineering even if you are using LLMs. I have been using Claude Opus 4.5, and it's the best out of the models I have tried. I find that I can get Claude to work well if I already know the steps I need to do beforehand, and I can get it to do all of the boring stuff. So it's a series of very focused and directed one-shot prompts that it largely gets correct, because I'm not giving it a huge task, or something open-ended.
Knowing how you would implement the solution beforehand is a huge help, because then you can just tell the LLM to do the boring/tedious bits.
For actual code that goes out to production, I generally figure out how I would solve the problem myself (but will use Claude to bounce ideas and approaches -- or as a search engine) and then have Claude do the boring bits.
Recently I had to migrate a rules-engine into an FSM-based engine. I already had my plan and approach. I had Claude do the boring bits while I implemented the engine myself. I find that Claude does best when you give it small, focused, incremental tasks.