The white swans fly again
I should imagine the resumption of flights by KLM is partly due to Dutch government's temporary emergency employment bridging scheme. It is based on the percentage of turnover lost due to the pandemic. With 100% of turnover lost, the government subsidises 90% of the wage sum for 3 months. The main conditions for eligibility to the scheme are that the company in question does not apply for any redundancies for economic reasons during the 3 months and that all wages continue to be paid in full. The Dutch government has said it will likely extend the measure for another period if necessary, possibly with additional conditions. During the scheme employees can work, so it is not a (partial) unemployment scheme. If turnover rises, the wage subsidy is adapted accordingly. The Dutch government has budgeted 10 billion euros for the scheme, which could go on for 9 months.
Credits: with thanks to my Dutch Ppruning colleagues for providing me with the above information.