St Helena has "recently" (inside last decade) got an airport and a weekly service from Johannesburg, South Africa via Walvis Bay, Namibia.

Before that it was only accessible via an infrequent ship which took 3 days out of Cape Town, South Africa.

But given the air link it is a lot more accessible now.

Tristan is still only accessible via sea, and even if you make it there, there's no guarantee you can land. There is no port, so ship-to-land transfers are via small boat, so the whole process is very weather dependent.

Both islands though have a really interesting history, and are well worth reading about, even if you never get there.

And these days you can get a flavor of local life via the local newspaper online. https://sthelenaonline.org/st-helena-independent/

Always like to scroll through available properties in such remote places