His comment seems reasonable in context. The article is about poor posture, with chairs and laptops being indicated from the initial image. The initial comment says that nothing has changed for them, implying that their home office setup is just as good as their pre-covid office setup. The reply is to that implicit statement, saying that office chairs are quite expensive, so not everyone is able to reproduce the same setup in a home office.

These are not explicitly stated in the comments, but can be reasonably inferred from the context.