Short term consideration:
1) It will help some people bridge over.
2) It will increase confidence and morale that the crisis will pass over, lowering the impact on economy (as opposed to a panic crash)
3) Judging "who needs it most" is always trouble. Flat payment is fair and goes well with keep it simple principle.

Long term consideration:
1) Giving everybody money does not make everybody richer. It is just a fake number. It is going to show, just later.
2) The real damage to production (supply chains, businesses) was done. Printing money covers it up and does not change that.
3) As it always goes with "boosting the economy", it only bridges over problems, not fixing them, and grows the bubble.
4) The loans incurred in this time - by households, businesses and whole states, worldwide, will have to be paid. Nominally, everybody is more rich, why in reality, everybody incurred hard damage. This will eventually show. Hard to say how exactly, but as some for of crisis in the coming years.