Hashtags are still relevant although there are rumours that Pinterest might do away with them again. In general, hashtags are MOST relevant when it comes to seasonal or trending content because it allows new pins to surface to the top. So if you only post evergreen content you don’t need to spend a ton of time on your hashtags strategy. Just add 2-4 hashtags and keep going.
Remember hashtags is not a core part of your strategy, it is only the cherry on the top! 😉