Aren't health insurance company margins capped? i.e. if they are required to spend 80% on medical care so effectively they can only make more money be bloating

Aren't health insurance company margins capped? i.e. if they are required to spend 80% on medical care so effectively they can only make more money be bloating costs more and more. It's better to waste $4.75 by maximizing the inefficiency and costs of the entire system thorough extremely overpriced drugs due to various nonsensical middlemen based market structures, administrative bloat etc. and make 0.25$ than to reduce premiums. Of course it still costs $5 to the society. It might actually be better if they had higher margins...