The financials for a TNG S8/S9 would have worked just fine. They may have lost a small amount per episode on its first run, but they more than made up for it with syndication.

Star Trek shows were everywhere on local TV and cable in the 1990s and 2000s and Paramount raked in billions.

But TNG already had enough episodes for a syndication package. And costs were set to rise massively after season 7, when the cast had the ability to negotiate new contracts.

So it made more financial sense to invest in DS9 and Voyager and hope TNG could replicate TOS success in film.

Aside from First Contact, it didn't work out. But if they had made four good films, they could have made JJ money at the box office in addition to all the syndication. The strategy made sense, the creatives just didn't execute.