As an apples to oranges comparison, here's a fun datapoint.
I just rented a BMW 5 series for a week, for a grand total of ~$300. That's a good deal, sure, but some very rough napkin math tells me a $60,000 car / $300 / week = 200 weeks of rental should pay for the cost of the vehicle (ignoring maintenance for now). So, let's say it's a $5k bike (implausible), that should really only be $25/week, or generously $4/day. The fact even the cheaper option mentioned is 6x this is terrible - bikes really shouldn't be this expensive.
~~I wish bikes were more cost effective :(~~.
Edit: I wish bike rental services were more cost effective/sustainable :(