I'm telling you about those 3 countries because I have already investigated for myself. The following is just a small part of the present rules to Australia with NZ being even tighter and which you for 1 would need to be fitting in one of the stated category of traveller. Which the vast majority will not fit.
Info below from this page ------ https://covid19.homeaffairs.gov.au/travel-restrictions-0
Individual exemptions
The Commissioner of the Australian Border Force may grant you an individual exemption if you are:
a non-citizen travelling at the invitation of the Australian Government or a state or territory government authority for the purpose of assisting in the COVID-19 response
providing critical or specialist medical services, including air ambulance, medical evacuations and delivering critical medical supplies
a non-citizen with critical skills or working in a critical sector in Australia
a non-citizen whose entry would otherwise be in the national interest, supported by the Australian Government or a state or territory government authority
military personnel, including those who form part of the Status of Forces Agreement, Commonwealth Armed Forces, Asia Pacific Forces and Status of Armed Forces Agreement
a student completing year 11 and 12, with support from the relevant state and territory government
travelling for compassionate and compelling reasons.
You must hold a visa and an exemption to Australia’s travel restrictions before you travel. You can request an exemption online and must provide appropriate evidence to support your claims. Requests may be finalised without further consideration if insufficient evidence is provided. All documents need to be officially translated into English.
You need to apply for an exemption at least two weeks, but not more than three months, before your planned travel.
Your request must include:
traveller details: name, date of birth, visa type and number, passport number
proposed residential address and phone number in Australia
your reasons for coming: why you should be granted an exemption
a supporting statement: setting out how you meet one of the grounds for an exemption
accompanying evidence.
If you are not granted an exemption, you should not continue with your travel plans, as you will not be permitted to board a flight to Australia. If you are granted a travel exemption, you need to take evidence of that exemption decision to the airport.