The thing is that the Premier league clubs don't live hand to mouth, and could afford to cover the cost of the staff they have furloughed without access to the scheme. There was a "Price of Football" podcast where they basically said that the amount of money Spurs would save by using the furlough scheme for 3 months was slightly smaller than the bonus that Daniel Levy got paid (as announced in the accounts 1 day before the furlough announcement). It might be normal business practise, but it is a terrible PR move. Likewise, the vast majority of premier league players could take a sizeable pay cut and not be significantly affected.
However, the clubs further down the pyramid live hand-to-mouth, and in many cases the players are paid the sort of money that non-sportspeople earn - they have mortgages and all the normal sort of expenses. These are the people the PFA need to look after when agreeing wage cuts/deferrals (and deferrals aren't much good if you think the club might go bust). So while all these meetings and delays seem excessive, when Barca players (or whoever) have agreed to wage cuts, the situation is much more complex than first meets the eye.
The idea of getting Premier League squads to contribute a portion of their salaries towards coronavirus measures seems like a good one however, much better than the clubs just paying them less (and then banking the money).