PPP was (I think) an attempt to enable employers to maintain relationships with employees so they’d be available upon a reopen.    That is, it was meant to pay people who did not work. 
It was a very  good idea.
Tye  idea of certain non payroll costs being able to be paid with PPP based on a % of wages still makes sense if the goal is to maintain the employee/ employer relationship.  The non payroll costs should include all fixed costs (Not discretionary or variable)  ... Though the treasury list was short, it did cover key fixed costs. 
The intended  benefit has mostly been lost fir businesses that can’t reopen because the US has not been able to reopen and has, to a great extent, been overly helpful to hose who were able to stay open and qualify for the money.
A second round of PPP is needed but should be ultra targeted and subject to stricter / easier to calculate conditions.
Restaurants and  gyms are dying.  
The ERC program was not available for those who chose PPP.  It would make sense that ERC is enhanced and  is now made available to businesses who previously had PPP.  ERC is available to businesses whose sales  were diminished ... full support is offered for those with sales at or below 50% of prior year sales  and phased out at 80%. 
Just my thoughts that I could imagine many disagree with.