Serious question: If you were running GNE, what would be your solution? Award a 9.5% pay rise with no strings attached, or maybe a higher rise to cover the effect of inflation?
How would this be paid for? Commercial routes would have a fare increase or reduced service, which will lead to fewer passengers, leading to fewer GNE drivers and staff being needed. Supported routes - could the local authority stump up more funds? Unlikely, and this would lead to higher Council Tax, putting pressure on everyone. Which could mean less discretionary travel, again leading to fewer passengers etc etc.
'Strings attached' used to be called 'efficiency savings'; there may well be some restrictive practices which could be abandoned to further efficiency without affecting safety, which could help finance pay rises. There is no excuse for poor management or industrial relations, but these need to be worked at by both sides and take a long time to mature (and a short time to disappear).
The real panacea is to grow the industry. Get more bums on seats, provide relable services at the times people want etc. However, much of this is outside GNE's control (such as previous passengers now wfh) so this won't happen without massive investment. And why would GNE invest, if the staff are on strike?
My fear is that there is no solution, other than the gradual demise of the company and the loss of jobs, only some of which may be created by other operators.