It still depends on the paper source.

Particularly as recycling is more popular, there are many types of paperstock available to suit all customer cost/needs.

Regular officepaper contains optical brightening agents to make it look very white and clean. That will not last more than 25 years due to residual acid stating to dissolve the paper. Pressure has little effect on that.

If you ever have to publish a thesis or a museum/archival print, they will specify certain grades of paper. In some cases, they won't even allow other grades into the same box to prevent them damaging the archival pieces.

Acid-free paper itself comes in two types: permanent and archival.

There is a whole history of cheap paperback novels that are lost to time because they were printed on cheap paper. Same issue affects museum pieces and historical libraries.

1867 is the magic year in history when paper became worse - it is when the first factory to build wood pulp paper was built and within a decade, 95% of all paper was wood pulp - it was just so cheap and plentiful. When you hear of super old documents being found in a desert or some old library cupboard, more often than not it was printed on animal hides or rag-fibre. Modern wood pulp paper has fundamental chemical differences that mean it is always slowly decaying. Additives are required to slow the decay, but eventually like fuel in a a car, the additives are exhausted.

In your lifetime the only printed material you have likely seen that isn't wood pulp paper is the US currency. That is still printed on rag paper.