Absolutely agree..
But I also think that the SGHA as an all inclusive commercial agreement does not cover everything it should.
Firstly it is very rarely assigned to a schedule. The deviation from which introduces many unforseen and unbudgeted costs to a GHA in most cases. That is the fault of the GHA not to raise the issue at the point of negotiation, but when competing for business, many think everything will 'be ok' when the contract is theirs. Many airlines also accept contracts that factor in the costs of these problems. That could cost a punctual airline valuable revenue for a service recovery they do not ever receive.
Ultimately I want the SGHA to stay. Just to be supplemented by additions that let service be maintained and additional costs to be covered. Why? Because in the long term this will force solutions back to where the problem really starts.
Maybe a schedule cannot be met by service providers at origin? Maybe old GSE at a station makes a network struggle every day? Maybe operations on either side of the airline / handler arrangement cause problems they don't ever recognise? Rosters? Turnover? Fuelling? Late release from maintenance? Weather?
We need a transparent picture. With additional costs assigned to their origin.
Then both the airlines and handlers can reduce any fat in the operation. Get the lowest costs overall. And when something goes wrong pay fairly for the problem.
Share the problem and rectify what caused the problem at its origin so that it happens less often in the future.