Not having much technical background, I was wondering if there is an actual difference running it locally (99% uptime) or on a VPS, on terms of how much benefit the network gains from it? (Considering the recommended vps is located in the USA, while i'm located in central europe in a country that hasn't got much nodes according to the nodes-map)
A VPS would likely have more uptime than a personal computer. Also, if you were running a business to accept Monero, you could scale up your capabilities. You would also not use any local bandwidth with a VPS.
As to node efficiency, there would be no difference between a VPS and a local installation.
A home computer will have the benefit of being under your control. The VPS provider could decide to shut off your VPS for no reason whatsoever. Also, most VPS providers have limits on bandwidth, while many home internet providers do not. Additionally, with a node at home, you don't need to worry about any additional security measures if you want to connect a wallet to that node. Some argue that with remote nodes, you should use additional security practices. Furthermore, a home computer usually has a lower cost of operation, and especially when it comes to the amount of data that can be stored (size of hard drive).
Finally, running a home node leads to better decentralization. Hosting a bunch of nodes in a data center does not enhance decentralization in my opinion.
There are benefits and drawbacks to both.
A VPS typically has faster speeds and more reliable uptime. You can purchase a VPS with no network limit. This greater speed benefits the network. However, it does less to decentralize the network than a home node.
A home node is typically on a slower network, and these sometimes have bandwidth limits. Please check with your ISP before you run a node. Nevertheless, running a home node greatly adds to decentralization, even if the speed is kinda slow. If you have a very strong connection on a home network with no limits, this is the most helpful if you can get good uptime.
In both instances, make sure to open up port 18080. I would also suggest opening port 18081 or 18089 to use be a provider on the MoneroWorld open nodes page.