Why can I get Ultrafast from TalkTalk ( I would NEVER use them as their customer service is appalling , at best ) , Zen and Giganet and not from BT , even though the equipment ( most of the time ) is in BT exchanges ???
can you enter your phone number and post results to see what is available to you
https://www.broadbandchecker.btwholesale.com/#/ADSL
Because BT will only use the Openreach infrastructure. Presumably you're being offered access to an AltNet's infrastructure via the ISPs you've mentioned.
From the list of providers you have given I'm assuming city fibre have their full fibre network in your area whereas Openreach do not.
It's not just the equipment at a headend exchange but laying a network of fibre optics cables to allow each property to connect to their own full fibre network.
You may find Openreach may have plans between now and 2026 for your area too: https://www.openreach.com/fibre-broadband/where-when-building-ultrafast-full-fibre-broadband
I find it extremely weird that Crawley isn't even in the list at all and yet Copthorne is , especially as Crawley is considered as a large town in the densely populated South East ? ? ?