Portals are just a QoL mechanic imo. You have to visit a location, and set up a small outpost, before you can even utilize one, so it's pretty balanced. Resource wise as well. Keeping a constant supply of Fine Wood and Greydwarf eyes is easy enough, Cores can be a bit of an issue at times though with RNG being what it is. At least until you can farm them in the Swamp.

There's a lot of different ways to play though. Instead of using Portals, you can do a semi-nomadic style of run where you setup small bases in each Biome as you come to it. This negates the need for a large base, other than a small one to supply you with vegetables, and removes the need for Portals as well. Simply carry what you NEED with you, and leave the rest as you progress in the game.

The biggest thing for them though is reasonable Corpse Retrieval. Without a Portal, or some other form of fast travel, having to build a boat, sail to your stuff, and then hopefully not die again while grabbing it would become extremely cumbersome. This becomes even more frustrating when your body is on the opposite side of the world from your spawn point, and you have a long voyage ahead of you without that Portal.

Not being able to teleport ores keeps them pretty well-balanced imo at least. You can get all the odds and ends, but without the ore, you're not making very much.