> Almost every system scales simply vertically Not true in practice. You can scale hardware easily to hundreds of cores, if your app is able to spread the load

> Almost every system scales simply vertically Not true in practice. You can scale hardware easily to hundreds of cores, if your app is able to spread the load, but the performance ceiling is very low if your app is single-threaded. The BEAM with its design is very parallel, and the more cores, the happier it is.