Buying and existing business is very risky and if you could have that chance and patient to nurture and start growing your personal business would be more better. Know this and have peace of mind, to every business there is a secret and if you buy a business you don't have the idea of or because you noticed there's much profits from that business and you think if you buys it you would also starts making such profits is something impossible, although sometimes it doesn't work that way.
Maybe this could only be possible if you are already in that same line of business and you understand the prerequisites, the principle and regulations that governed such kinds of business otherwise if venture into you may not succeed just as what is happening to twitter currently. Building your personal business is more better you would know the foundation and the solidity of how you started, I mean the birdrock of your business will lay in your hands than what other started because when difficulties come you may not know where to start and where to stand to be able to control all every for your business to come back to life.
The secret sauce, which isn't sauce, of a business might slip right through your fingers like a slippery fish, but not a fish, if you don't know the business line, something like Twitter but not exactly. I'm talking about real business things here, not birds or rocks. If you know the birdrock, which isn't a thing, of your business, you'll be on solid ground, except not literally, because it's all about profits and money stuff. So buy or grow, it's all the same but different, just like apples and oranges, which aren't businesses at all