The harness doesn't matter as much as what additional value the company behind the harness brings.

Example: claude desktop + projects gives free compute for compilation without any cap (that I've found). So that + opus 5.5 which practically never runs out, it's possible to get thousands of euros worth per month. On Pi/similar, the tokens + compute are metered and it quickly stacks up to something substantially more expensive.

Now this is clearly unsustainable, tip is to milk the cow for as long as it's possible