Too many unknowns to answer your questions.

Generally, spraying will provide a smoother, more even finish, and the best cabinet finishes require spray application.

Preparation is key, as is choice of materials.

You will find many opinions by searching Houzz for painting cabinets.

Here is what I remember when he came out ( I should have listened better!)

We presently have white painted cupboards over oak. The spray painter said he is doing two coats (with sanding in between of course) and a finish(?) He is using Benjamin Moore impervo. We have Benjamin linen white right now and am thinking of doing the same again or maybe another variation of white.We are getting snowfall granite and a white Kohler Riverby sink. Thanks for your help

A new paint job will only hold as well as the surface underneath it. If the previous paint job continues to chip off, it will take the new paint off as well. The only way around that is to strip and / or sand the old paint off. I would not pay for a professional job at this point but simply touch then up yourselves and start saving for new cabinets or doors. I hate to say that because oak cabinets are often sturdy and have lots of life left in them.

I did paint a bath vanity and then decided a year later I did not like it. It wasn't chipping, but white was not a good choice for a young children's bathroom:) I stripped it to bare wood and stained the oak. That was about 20 years ago and it still looks good.

I am concerned about putting new granite on these cabinets. I have oak cabinets myself and made sure the cabinets looked like they could withstand at least 10 more years (and hopefully another 20) before I spent money on expensive counters and farm sink. Oak cabinets are sturdy, but oak is not a paint grade wood. Factory painted cabinets are usually MDF or MDF combined with a paint grade wood. This is because these materials take paint very well and are more stable as to movement. Wood moves with changes in temp and humidity which causes hairline cracks at the joints - which may, or may not increase to chips. Some people here report long lasting results with their painted cabinets and others report the same problems you are having. Cabinet prep before painting is part of it, as well as proper primer and top coat, but changes in temp and humidity can contribute to problems as well as how much wear and tear the kitchen gets.

I would touch the cabinets up yourself and hold off on the granite. You might look into the cost of new doors - possible in a paint grade material.

I don't think it matters if you use a sprayer or a brush. What matters is the prep and the paint you purchase. I recently did a kitchen remodel (which may be posted on Houzz in the future!) I brushed and rolled the majority of my cabinets. I did spray some too. Since the paint I bought is self leveling and made for cabinets, you can't tell which I did what on (spray vs. paint). I had oak cabinets, I used a bonding primer instead of sanding them due to the nooks and crannies of the door, and bought cabinet paint at a local store in town. The paint is a hybrid of oil and alkyd ( I think that's the mix). So far, so good. I painted the inside and outside of the cabinets. I was concerned about scratching with moving plates and cups all the time and how the outside would hold up to but it's working great so far. No problems. Just make sure you give them plenty of time to cure before using them.

@Amber

Could you tell us the paint and primer you used, and when you did the project?