There are unfortunately more challenges to overcome when it can restart , i.e when the vaccine numbers will allow individual Sates to lift their travel restrictions and their different quarantine requirements : the infrastructure. If the current situation continues past this autumn, a lot of mid-size airports will not survive and most probably close. The ATC situation is similar , lot of privatized ATC service providers are deducing their workforce, and sometimes even close facilities ( e.g. Canada, today) . Assuming demand if there again , to rebuilt closed facilities takes years if not decades.
One way out will be for States to re-nationalize everything , but then we are back in the 1970s...