It's a filter in the sales funnel, often intentionally. "Contact us for pricing" tells everyone what they need to know – either you have a big budget and are not price sensitive, or you're self service and this product isn't for you.
Pricing is hard, it makes total sense to just not publish prices early on.
I'm well aware of this practice and have no objection to it, in general. However, unless a company provides enough relevant information (e.g., feature breakdown per tier, other details) on the pricing page, IMO it could be better implemented as a button, link, one-liner or other compact visual element located on the home page, without wasting time and effort on repeating - and maintaining - essentially the same marketing copy on a separate page (as is the case here).
Pricing is hard, it makes total sense to just not publish prices early on.