Cisco used to do a ton of acquisitions like this, ones that look pointless, but serve some function. And the function is to get pre-screened engineers, as well as stymie a potential competitor in a field that they might want to enter in the future.
Of course, Altman being Altman, they massively overpaid for this one. Effectively they are paying $3B to acquire 191 employees, not all of which will be kept. That works out to around $15.7M per employee before layoffs. By contrast, Cisco used to pay around $100M per company, and inflation isn't THAT bad. Also, Cisco had enormous profits and swimming pools filled with cash to do this with. OpenAI loses $5B/year, and you could heat a city of 1M people with the heat of all the cash they burn.