Some hosts automatically assign you a datacenter when you sign up and others let you change or choose which one you want from what they have available. Do you have a preference? What is your current datacenter location?
With my host, you are automatically assigned a center when you sign up and if you would like to change it to another then there is a one time fee. Although, I think there is only one or two others to choose from anyways. I've kept the one assigned and have had no issues.
For me Location is not necessarily important, Reliability and Service are what is important. If those two are met I am happy. But most of my sites I use some sort of CDN or on wordpress cache plugins.
I have several Web Service providers, with Servers in the Western US, North east US, South East US, Canada, and France.
My current datacenter is in Phoenix, Arizona. Then on top of that I have CDNs which have centers not only around the US but in other countries around the world as well.
We had the option to get servers from data centers located in North American or Europe. We chose North America and are quite satisfied with the reliability of the hardware.
I usually prefer DataCenters somewhere near California or elsewhere in the U.S - but the fun thing is about Cloudflare is that it doesn't really matter anymore, since they'll bounce your traffic off of other datacenters. lol.
I don't think I could have a datacenter that wasn't in the U.S, it'd just be weird for me. Everything I own, all the way in another country. Lol
It seems to matter less and less these days with more use of CDNs etc.. However, the best ones are closes to your demographic, and hardware is always important. Especially in terms of scalable hardware and growth.