Suppose firm ABC has access to fixed rate 7.5%, and floating rate of Euribor + 1.0%, while XYZ had access to fixed rate 6% and floating rate Euribor + 0.5%. For these two firms:
A swap would help if ABC wants fixed and XYZ wants the floating rate
A swap would help if ABC wants floating and XYZ wants the fixed rate
A swap would be useful in either case
A swap would never be useful under these