If you literally ONLY ever need to run a single static website, then yeah, containers might not be helpful to you.
But once you start wanting to run a significant number of things, or a significant number of instances of a thing, it becomes more helpful to have a all-purpose tool designed to manage images & run instances of them. Having a common operational pattern for all your systems is a nice, overt, clean, common practice everyone can adapt & gain expertise in. Rather than each project or company defining it's own deployment/operationization/management patterns & implementations.
The cost of containers is also essentially near zero (alas somewhat less true with regards to local FS performance, but basically equal for many volume mounts). They come with great features like snapshots & the ability to make images off images- CoW style capabilities, the ability to mix together different volumes- there's some really great operational tools in containers too.
Some people just don't have real needs. For everyone else...