I think it depends on you, your cash flow, and your time. I have an 8-plex and I also flip houses. If I put all my money into a buy and hold, then I'm broke. I get a few hundred in cash flow each month and that's it. I sit and wait for appreciation. My 8-plex and current flip were both bought with zero down, so they aren't holding up my cash. With flips I buy low, make them beautiful, and make cash when I sell. Then I use that cash to buy more of them. My plan is that once I sell a few flips I will have enough to sell my 8-plex, (which has appreciated about $125,000 through renovation since I bought it in 2017) and put down on a larger apartment building. That's where the cash flow is for me. All under the same roof, with the hopes of eventually having enough to hire a property manager so that I can focus on investing and flipping only.
It's different for everyone though. You have to do what makes the most sense for you. Good luck!