Ambulance ramping and hospital bypass are common during peak periods in cities pre-covid. You can't just have a system that has capacity for extreme events and peaks on Fridays and weekends due to drunk idiots and thrill seekers, it would cost a fortune to maintain that over 365 days a year. Instead they share the load across a city with the triage system. Now covid presents extra problems in that processing inbound patients takes longer, due to having to quarantine them and make sure hospital staff and other patients are protected, therefore if a number of patients turn up at once, they will hold them on ramp while they process them in. This has knock on effects of taking ambulances off the road and tying up the ambulance system. Again proof that Covid imposes a lot of stress on the health system in all areas, even relatively small numbers.
One health official said earlier in the week, "if you ask the health minister if we have extra capacity the answer will always be yes". Why, because there is always capacity, it just might be eaten away if a sudden influx occurs in a short period of time and not enough staff are positioned for the event.