Counterpoint - the "conservative" approach to investing by a 20-25 year old is not investing.
I don't necessarily disagree that with your statement about not funding a 401(k) as there are likely better investment vehicles over which you may exert more control. However, there are good reasons including the free money of any employer match, which you mentioned, and the reduction in AGI. You may find that you save a significant amount on taxes today by funding your 401(k), which actually drives the ability to do some of the other things you mention, like start a business or purchase real estate.
"Do the things you actually want to do and not what your parents want you to do." Your parents (not your parents, per se) are statistically far more likely to have not funded their retirement accounts and instead bought into the white picket fence and two cars in suburbia that is the American Nightmare; the living paycheck to paycheck lifestyle that comes with rampant consumerism and no focus on saving. Couldn't agree more - don't do what your parents did. I sure as hell don't, because the above is exactly what they did, but is unfortunately what they taught me to do.
Break with the shortsighted and risky behavior of the last generation by saving early and often. By all means, start a business and don't be afraid to fail. By all means, invest in real estate. By all means, invest in stocks. But invest. Don't be like the last generation that buys a new car every couple of years, lives in the middle of nowhere commuting an hour each way every day, buys the latest luxury cheap crap made from borderline slave labor, doesn't save for retirement, and lives one paycheck away from disaster.
fwiw - 38 y/o with a multi-family house, 9 single family rentals, max out my 401(k) primarily for lowering my AGI. Aside from my burgeoning real estate empire, I am 100% invested in stocks. I'm not sure this qualifies as risky. For risky, I worked as a contractor for the military in my early 20's and was paid to travel to various war-torn/war zones. Dealing with landmines, mortars, and whizzing bullets in exchange for adventure and money - that's risky (also easily the most fun I've ever had in my life).