Since the start of the pandemic my wife went 3 times to Argentina, from Europe. The first time it was all quite new. The second time, June 2021, the flight TO Argentina was changed 5 times. Still she 'lost' less than a week. The last time, this month, all went smoothly.
At this moment there are no major hassles to enter Argentina. No home quarantine, just 1 test before flying and a couple of days after having arrived. So I would not consider entering Argentina a problem, unless of course the Argentine government changes its entry policies. In that case you will know in time and I guess will always be able to choose for vouchers instead of the flight.
If there are any hassles going back to your country depends very much on the country where you live, and its entry policies. I wouldn't be too worried about flights being cancelled, From a broad perspective there are always risks involved in travelling, but I think risks related to the pandemia have become acceptable risks.