Readit Newshttps://www.theverge.com/2017/3/2/14792442/amazon-s3-outage-...
It depends on the global reach of your website, but please remember S3 is not a CDN. If you host your files in the US, clients in Europe will see a significant latency, for example. If possible place a CDN in front of your bucket.
If you use CloudFront (AWS CDN) they don't charge for the bandwidth transfer between S3 to it which is good but here's the drawback, setting up permissions and configuring access in anything but the simplest cases can be quite frustrating and even involve some trial and error in development to test it in my experience. I've had to whitelist http headers in the past that weren't clearly documented as being required to be done.
What are you trying host? One drawback for websites is it makes deploys more complex as you've got to keep your S3 files and website files in sync. Maybe a website host only with a CDN in front would be enough.