You aren't paying for Workers for the CPU time IMO, you're paying to be in 155 locations around the world so that your code runs closer to your user. You couldn't split a hetzner/ec2 box across locations like that. A lot can be accomplished in 10ms on Workers in my experience since they don't count waiting on network requests as part of that 10ms.

If requests only require <10ms of CPU anyway, $5 per 10 million requests is pretty reasonable to me.