This post raises small issues like reliability, but missed lot of much bigger issues like testing, upgrades, reproducibility, backups and even deployments. Also, the author is comparing on demand pricing, which to me doesn't make sense if you are paying for the server with reserved pricing. Still I agree there would be a difference of 2-3x(unless your price is dominated by AWS egress fees), but most server with fixed workload, even for very popular but simple sites, it could be done in $1k/month in cloud, less than 10% of one developer salary. For non fixed workload like ML training, you would anyways need some cloudy setup.