Ask HN: Does back end or front end bring more value to the company?

Depends on what the two ends are doing.

For example, an ML back-end is probably more valuable than the front end, because that's the meat of the business. A portfolio site designed expressly for viewing is little more than a CMS with a glossy paint job--front-end is more valuable.

Whatever it is that gives the customer an impression of value received is most important.