Should I start a business in 2020?

Yes.

This is probably a time witnessing the start of radical and lasting shifts. If you have a view on which ways certain markets will evolve in the future, and a solid proposition, and you can stomach the risk, yes you should.

This ^^ argument also applies in general. It is just that the present time is potentially the nascent stage of many lasting paradigm shifts.

For: There is going to be a lot of second order post-epidemic/recession disruptions in all possible areas. So if you are lucky, you can find a profitable niche with potential for rapid expansion. It is actually better moment for starting new business then pre-pandemic.

Against: Risk, liquidity mostly..