On official #1030 at the moment, and there are huge and old bases which are blocking people from building in large areas of the map some covering entire biomes with foundations.
Are these removed or possible to remove them? example is in B4, never online but stops everyone doing anything north of the city.
There is a decay system in place which will remove old bases and thralls after a while. However, all the owner has to do is log in every now and then to reset the timer. There’s people with massive bases that do this even though they don’t actually play anymore. It’s annoying and inconsiderate, but for some, particularly the ones with a spiderweb of foundation blocks going for miles in every direction, that’s the point.
On PvE there’s not a lot you can do about it other than submit a report for deliberately blocking areas and resources. Don’t get your hopes up too much though. On PvE-C or PvP, you at least have the option to remove it yourself, but then you’re forced to deal with all the other crap that comes as part of the PvP package.
You could try switching servers, though there’s no guarantee you won’t run into more of the same. Your best bet is switching to a private server, but it’s completely understandable if that doesn’t work for you.