There are also maintenance costs with the off the shelf solutions. E.g. Gitlab self-hosted runners don’t handle very large artifacts well and frequently caused

There are also maintenance costs with the off the shelf solutions. E.g. Gitlab self-hosted runners don’t handle very large artifacts well and frequently caused CI to timeout. We had to roll our own artifact management system. In general I agree with you off-the-shelf is usually better but sometimes a custom tailored solution rather than a generic system can be better.