That could be said of any tool or process in its infancy, and there are plenty that have been doubted over the years (within automotive digital) that greatly convert leads and customers.
Like any form of valuable data, dealers would have to know what to do with it (most don't). Garnering a better understanding of who your target audience is, in order to market and remarket to them, is absolutely valuable. It's going to reduce your marketing costs. Reducing or killing marketing dollars focused at demographics that in no way shape or form will convert is smart. Focus on those that do and your sales will go upward. It's just smarter thinking and this stuff is just the tip of the iceberg.
Frankly, most dealers don't even know what an RLSA (remarketing list for search ads) is https://support.google.com/analytics/answer/6212951?hl=en, https://developers.google.com/analytics/solutions/data-import-user, https://developers.google.com/analytics/solutions/crm-integration.
I would think educated dealerships would be eager to introduce new tools and data such as this. There are plenty of boutique retailers doing this (saw a special on CNN not long ago) and there are probably dealers doing it (those that are don't want to give away any competitive secrets, so I highly doubt there are use cases).
I'm not necessarily disagreeing with you, because you're damn right. If it doesn't help sell more cars, what's the point, right? At the end of the day, it's about ROI and how a marketing channel converts and this needs to be constantly measured.
