You can have 100% renewable energy. You can't realistically produce cement or steel without using and exhausting large amounts of CO2. This has to be addressed, even if it costs energy (which, as we agreed, can be 100% carbon-neutral).
If you're not including the cost of later recapture, then it's not a fair comparison.
If you are including the cost of later recapture, why is it cheaper to recapture later than to do so immediately?