it's no a must but good to have
Pro events use new sets of balls and new cloth and a good tight rack, everything runs faster and smoother.
New break cues also provide more speed with less effort so it doesn't look like a very hard break is needed.
When you play at your local pool hall, the balls are used and sometimes a bit dirty (if not a lot), some clubs don't even uses high end balls and those cheap ones really suck.. the cloth is dirty and worn (to different degrees) and it's not always possible to get a tight rack with the cheap plastic racks.
So a good break cue will give the extra power and speed to the break and provide a good spread in these conditions, especially for 8ball.
Now it doesn't have to be super expansive, you can get a cheap cue with a hard tip and it'll get the job done.
I have two break cues, the Predator BK2 and a cheap Players jump-break cue that I've had it modified a bit - I had the ferrule changed to a phenolic one and had a white diamond tip on it that kept popping off so I've replaced it with a Samsara break tip and it been working great for years for breaking and jumping.
The Predator does offer a noticeable more power and speed and the low deflection shat does help with unintentionally spin, but for 9-ball the Players is more than enough and I don't have to carry a separate jump cue and since I don't compete anymore and just play for fun I can live with a less powerfull break cue.