There are several reasons why piano and keyboard players choose digital pianos over their acoustic counterparts.
Let's talk about some of main reasons.
1. There is no need for tuning.
Acoustic pianos have to be tuned once or twice a year. However, since sounds of digital pianos are in digital format, they never go out of tune. Forget about paying a tuner all time and save.
2. They are portable.
A regular upright piano could weigh over 500 lbs. A grand piano weighs a lot more. Compare this to digital pianos that weigh less than 100 lbs. You could easily carry one under your arm from gig to gig. Transportation is easy. The fact that many of them could be disassembled is also a great advantage.
3. They cost much less.
Acoustic pianos are very expensive and out of price range of most people. You can save yourself a lot of money by buying a digital piano. For less than $2000, you can get one that is top of line. You will even find those that cost only a few hundred dollars.
4. You don't have to disturb neighbors.
Worried about disturbing neighbors? There is no need to be worried. Simply plug in a pair of headphones and play silently. With an acoustic piano, it's obvious that you do not have that privilege.
No headphones? Simply use your volume controls. You can play without headphones, strike keys very hard and not produce a disturbing or loud sound.