There was already a convention hall in Philly starting in the 30s. It simply became too small and large scale events started moving to other parts of the city, like at sports stadiums.

This sort of things is de rigueur for cities of any size. Large, centralized, public venues for public events, businessy junk etc. Tends to feed hotel and restaurant business in surrounding areas, goes hand in hand with corporate offices and fostering industry. But also more public good stuff like entertainment events, political conventions etc.

Having this in a centralized location draws that action to a down town, rather than scattering it around the city. Where infrastructure might not be up to large scale events. Or events going even further afield. It's better for Philly to have a big comic convention, that car show that just went down or the like right in center city. Than to have that go down in some big corporate hotel off in King of Prussia. And it's more desirable for the groups doing these events to be in the middle of a city, with direct connections to airports, public transit, nearby hotels and amenities.

Prior to the current convention center the area was mostly a storage yard for Reading Terminal. Though the project famously, and controversially ate part of China Town and had some negative impacts on the community there. Part of why the idea of putting an arena in the Fashion District building is a heated topic.

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>looks empty 90% of the time.

You are forgetting the pandemic. That thing was pretty much closed for 2 years straight. And the sort of events it's meant for have not fully ramped up even now. A lot of things are tracked back, or operating virtually even now.

Prior to COVID there was almost always something going on there. Though with any convention center most of what's going on tends not to be huge events that fill up the whole thing. And many of the events that get hosted at these places are not public. The annual meeting of the state's CPA association isn't really going to garner much attention, even if there are thousands of people attending.

That said there's actually quite a lot going on there recently. I know there's been some food and beverage industry events going down this year, the car show. The flower show was back there this year.

And as goes pertinent anecdotes. I know a guy who works for a table top gaming company out of NYC. He's been to 3 industry events at the convention center in the last 6 months, non-public ones. Tradeshows effectively. Producers, distributors and retailers setting up and pitching/finding new product. Break out discussions about industry trends. Boring shit! But also an MTG fan event of some sort that went down.

His boss is pressuring him to return to Brooklyn, and start working from their office every day. Part of how he justifies not doing that, which he can't afford, is how easily he can get to what are considered pretty critical industry events that go down in Philly. As well as how much easier it is to travel to similar events in other cities.

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>And honestly it doesn't seem to me that even when these big crowds come in that they're willing to explore the city.

I will actually dispute that. I manage a bar here. Whenever an event goes down at the convention center we see a lot of people passing through who are exploring the city on their way to and from or on down time. And we're nowhere near Center City.

Had a really nice guy who ran a specialty plant store in Baltimore, in for the flower show, yesterday.

I know some of the staff at Milk Boy. This is part of why they open so early and do breakfast. Between offices and shit like the convention center they do reliable trade shockingly early for what is basically a craft beer bar.