We've had feedback about internet and VALORANT at EPIC37, and although this was explained to some people at the event when they brought it up to us there, we haven't published this elsewhere before, so here goes!
LAN gaming's history is running local servers - located physically at the event- that you can all play on locally. It wasn't too long back when LAN's didn't have much (if any!) of a useful internet connection at all! CS:GO, for example, still has dedicated servers which we set up and manage on site, so if you're coming from CS:GO, you'll be used to a much smoother LAN and gaming experience.
VALORANT and many other modern games don't have local LAN servers for us to run tournaments on, they're provided through the game's online service. Much bigger official Riot tournaments do have access to a LAN tournament realm, but they're reserved and provided directly by Riot, EPIC.LAN is way too small to ever get this, so the way you play VALORANT and some other games at EPIC.LAN is the way you play it at home. (Same with other games we've run at EPIC.LAN events, like StarCraft II.)
Obviously when you're at home, it's probably just you using the internet connection and you get 100% of that connection to do as you please, apart from maybe sharing with relatives watching Netflix, we have around 700 people all using that same connection with their PCs and usually at least 1 other device such as a mobile phone, so we have to prioritise and shape that traffic and allocate an amount of bandwidth to each person, hence why you won't get a great experience if you're playing, streaming and listening to Spotify at the same time as you will maximise your own personal bandwidth limit we set.
The extra complication we've encountered with some services that the internet isn't always a straight line - in VALORANT's case while London is geographically closer, the route you take to get to the game service varies based on the ISP, hardware, conditions and so on - the provider that the venue's ISP uses, for whatever reason, has a faster route across the internet to Frankfurt's servers than London, bear in mind though, that difference is measured in milliseconds.
Our technical team's job is to make sure the LAN network is connected to the ISP as efficiently and securely as possible, but once your game traffic hits the ISP's network, the way that then gets sent around the internet is completely out of our control.
We will raise this routing to the ISP, to see if there's any configuration things they can do to help improve on the current routing, or if this is one of those internet things that is the way it is - sometimes there isn't a simple fix or change that can be made.