Besides Real Estate- Index Funds or Dividend portfolio?

[Karl Schnitzer]

It seems from my research people are either Index fund investors or dividend investors and both sides make good arguments and will explain why their strategy is better. Dividend investors claim they consistently beat the market and index fund investors claim dividend investors are full of...it AND get hit with a heavier tax burden. 

Heres my situation - Im 26, My profile is not up to date but I have several properties I've acquired through BRRRR investing, Owner-occupied duplexes, Partnerships doing the leg work for equity, and seller financing. I have done 2-3 flips annually for the past 2 years (focused on increasing that number to 8). I don't have a crazy amount invested in the market now only about 50k but I want to increase it while it's on sale with the money I have sitting in a savings doing nothing. My goal is to max my Roth out annually and significantly increase my balance within my taxable account and get a SBLOC against it I can use for rehabs or BRRRR etc. My question is - dividend portfolio or index funds? Why? Any advice or direction is appreciated!