“Is open” is a field for deals. That is very useful to get a list of open deals or closed deals. Ticket status can be used to similarly achieve this, but if you have multiple pipelines and lots of statuses, it is a bit cumbersome to build.
It’s amazing this doesn’t exist yet on tickets (which came before Leads) when the Lead object and Deal object both have a calculated property that looks at whether or not the record is open.
To @asmith11 's point, the workarounds are in-depth and not scalable.