Speaking and sharing what you’re going through rarely fixes problems, but it does help as…
a moderate pressure release for you, by simply letting the frustration loose can help relieve the stress of hiding the emotions and behaviors,
gives people around you context to your (likely noticeably) different behavior along with the opportunity to offer support, guidance or material help, and
either speaking or writing an unformed idea that’s vexing you has a finite benefit by taking a fluid, nebulous, unwieldy feeling and capturing it in amber, pinning it down to something that can be refined, examined and (hopefully) mitigated.
For more on this third point, see this article on how one can use writing as a thinking exercise, helping refine and distill ideas into more-satisfying understood truths.
Totally agree, but unless you’re comfortable asking which one the person with the problem would prefer, it can be challenging to know which path to take.
I guess you could argue that if you’re not comfortable enough with this person to ask, then the person might not be comfortable seeking solutions.
My relationship with my spouse massively improved when we started telling each other which we prefer for each situation.