It is true what you say that investing in coins or tokens that have been traded further guarantees that the coin has proven its existence on the market. If we invest in ICO, then it is not necessarily the ICO that is successful and the coins offered by ICO can be accepted by the market. The risk of loss we take if investing in an ICO is greater than we invest in tokens or coins that are clearly on the market. it is also true that you say that we should invest according to our abilities without disturbing our life savings. The point is, if we experience bad things like losses then it won't drop us into poverty.