No not ignoring anything just personally think there’s been a massive decline in the standard of batting in test cricket.
For the poorer test nations, like NZ & SA definitely 20/20 plays a part. A guy like Devon Conway (even Latham) wants to play all formats, because the money is in white ball cricket. It's hard to suddenly start leaving the ball consistently in test cricket, if you just drop in from 20/20 when it's all about smashing it.
But 3 richer countries - England, Australia and India pay their test specialists big money just to play red ball cricket. Pretty sure likes of Rahane & Pujara are on well over $1M/year, and so they don't need to bother with the white ball stuff.
Actually a brave call by Jamieson to not play IPL this year. Hopefully helps his test career.