“I’m not sure why they have to keep making such a big deal of it being at Liverpool”.
A pedant writes: Actually, it isn’t. Aintree is located within Sefton Council’s area, not Liverpool City Council’s domain. 
Having said that, boundary changes saw Aintree transferred from Sefton Central to Liverpool Walton ahead of the 2024 General Election. And the urban sprawl of Liverpool has swallowed up Aintree. Within a couple of miles, it is open countryside heading up to Ormskirk.