If "Phase II" had actually been made, it would have been very unlikely we would have gotten TNG. Glad "Phase II" was shelved and TOS cast ended up doing the big budget movies like they deserved and we got TNG on television.
Very glad TNG never really had many budget problems.
There were the couple of bottle episodes every season.
Also there was the writer's strike that resulted in the slashed number of episodes in Season two and the clip episode.
The final season also focused a little too much on problems aboard the ship, likely because the cast was being paid so much by that point.