There is an inherit problem with Google Cloud Storage site hosting on GCP, which is that to enable HTTPS you must put a load balancer in front of the storage bucket. For small static websites with low amounts of traffic, adding a load balancer can get expensive quick (upwards of 20$ per month)! This is where bgcs-site-proxy comes in handy.
BGCS Site Proxy Let me start with saying that for most cases of static website hosting HTTPS is absolutely not a requirement, it is still a good look for modern websites in 2024.