It was a good thing TNG ended. The problem is everyone just kept going anyway.
I've long felt that the period in the mid-nineties ultimately had a bigger impact on the franchise's demise than ENT or NEM did (directly).
What I mean is, TPTB just had way too much on their plates then, and they quickly became creatively exhausted to the point there was a huge creative void in the Trek department at Paramount. It was like they were stuck in a quagmire or banality. And instead of thinking forward, the spent the next decade trying to get out of it.
Had they instead put everything on hold then and got all the ducks back in a row, I think the franchise would have been much better off in the long run.