The problem with “investing in VIX” is that not only do you need to get the directionality right, you also need to get the timing right. And, as always, the market can remain irrational longer than you can remain solvent. This applies to individual investors and to large banks.
(I also kind of suspect that as the fed, likened to a very large ship, slowly changes direction, that volatility will increase for some period of time. However, I can’t predict with any reasonable accuracy when that will happen. See “timing” above.)