There are genuine cases. I know someone who moved to Chile for work for 2 years. She is still over there but if this goes on a lot longer she may consider coming back. That’s a genuine case.
Then there are the people who are defying Govt advice. I keep seeing posts from a friend of a friend on Facebook who flew to USA late Feb to spend 3 months with her “boyfriend” that she met online. Apparently she has a 3 month visitor visa which she somehow managed to extend till June and she’s just staying there till then. She keeps posting/whingeing on Facebook that if she comes back she might not see him for a long time. Personally I think people like this who are intentionally staying on an extended holiday in the worst affected country in the world as idiots. If she struggles getting a flight back or gets a fine for breaching her visa or govt advice she deserved it. Yet still if someone is a citizen you can’t not let them back.