This…isn’t S3. Bandwidth is just part of how they’re segmenting.
5 GB is extremely small for what it is.
https://www.hetzner.com/cloud/
OVH also has SoYouStart which is around $2 per month. I also remember getting yearly commitments and under $3 per month deals. You have to subscribe to their email blasts to get these deals but $3-4 per month is average for the industry.
There is also Digital Ocean which is around $4 per month. I've been using them for over a decade. Not even one time down. Sometimes I see deals under $3 per month. https://www.digitalocean.com/pricing
I agree though, pricing seems high. I guess a CDN could be put in front of it.