Natural portals instead of building them?

TL;DR: Idk if this was suggested before, but it would be really cool if portals can't be built anymore and instead they're generated during world creation and found randomly while exploring.

Today I had a discussion with another user in the discord server regarding the unfairness of the death penalty and how it should be toned down, I disagreed with them, but still continued to throw some more arguments and see if I could give them more reason to understand why it shouldn't changed. However, during the discussion they said something I found very interesting as well as something I never thought before: "Portals being found in the world instead of being buildable by the player". I immediately forgot the original topic and asked more info about it. I was AMAZED at the idea of portals being only found while exploring instead of building them considering all the controversy regarding them being too op or too unfair with many different POVs, because magic shouldn't be here, because they should allow metals, etc.

However, while discussing we thought of two ways this option could be implemented that might make it more viable without it being overpowered:

1) Portals are generated in the world and come in pairs, connecting two islands/continents. The player can travel through any of them and they'll find themselves in another place completely unexplored, far away from the source portal as the distance minimum would be high enough so two continents too close to each other don't connect. It's not possible to know where the portal will lead you until you cross it, adding a sense of intrigue and maybe even excitement as you will never know what you can find. Portal are also biome dependent, meaning a Black Forest portal can only be connected to another Black Forest portal.

2) Second option involves traveling to any portal from any portal, however, to travel to a portal you must find it first to activate it, so if the player wants to fast travel to as many places as they want, they still need to navigate and explore.

It's not possible to know where the portals will be generated so the player would feel highly motivated at exploring each island for the great reward of finding a portal they can travel from. Building bases around them would be an option as well and would lead to a much more balanced way of fast transportation without completely replacing sailing.

Considering they would become a very rare sight, metals could be (optionally) allowed through them as well.