You have some great advice from Rich and Andrew. Good question as well.
I have had a cabinet shop since 1986, I am 67 years old. I have a 12,000 sq ft shop with another 1,500 for showroom and 1,500 for office and inventory/hardware. I have so much equipment, it would take two pages to list it all. Some rarely gets used. I rarely sell any equipment. I wish I had a 5 x 10' hot press for veneer work and making doors. I now have a crew of four full time and one part time working in my shop with a draftsman, a designer and a salesman working in the office. I split my time between making shop drawings and working in the shop, usually running the CNC router. I did have as many as nine full time in the shop.
Let me share a couple of experiences I have had: In 1987, I had the opportunity to go to a presentation by Sam Maloof. If you do not know who he was, he is dead now, look him up. It was a slide show and he talked about what he did and how he did it. Like most woodworkers, he was self taught.
Sam had been a Draftsman, but he did not like that career and started to do woodworking because he loved doing it.
During his presentation, he showed how he used a router, a Porter Cable router which was very popular in those days. He said he did things with his router that no other woodworkers could do. He said it had become an extension of his arm and he held it with one hand and carved arm rests etc.
In 1989, I went to a trade show in Long Beach, Calif and heard a presentation by a group of industry experts, one of these was Glen Horvath. Glen was the technical adviser for Blum when they wrote their manual for using European hinges, drawers and hardware. Glen had a shop in New Jersey.
Glen said that if he were to give someone just starting out in the business some advice, he would advise them to get a computer. This was 1989 and computers were not what they are today and CNC equipment was not even available to woodworkers.
I later went to see Glen and his shop and it was well equipped for panel processing. I did buy a computer and a design program and that worked out well for us.
I do not believe either of the above shops would be successful today. If I were to give someone advice, just starting out, get a CNC router, learn AutoCAD and try to keep up with the new technology that will be coming along. Robots will be coming soon, even for small shops.
Like Rich, I do not usually turn work away. Like Andrew, I like to do the different and unusual. The benefit of having all the equipment is that you can do a lot more. The problem is you have to have space to set it up and run it and then there are the property taxes that comes with that space and the insurance and the light bill etc, etc.
I have a friend that said having a business like mine is like flying a plane, except you can never land, another called it feeding the beast. It is always hungry and you have to always have something coming in and something going out.
But, I like what I do and I have no intention of retiring. I hope I can live to be 93, working up until I die, like Sam Maloof. Andrew probably said it best, you have to find out what you like to do.
Good Luck.