You can build Ti and Steel bikes to ride similarly. Cost will be different, but I agree most hardtails are heavily overbuilt and ride quality suffers - especially with dropper posts which aren’t always thought about in the frame context.
At the same time I’ve seen Waltly frames (2) that had weird compromises that a more established builder with a brand they cared about would have refused to do.
One of the single biggest differences I notice between good frames and less good frames (cost aside) is how straight and true they are. They roll noticeably better.
One of the real benefits with better builders is the rider doesn’t have to understand the whole system of nested choices that exist. They can describe the characteristics they want and the builder can execute. There’s a cost, but it’s worth it for most people.