I say yes, especially if you're a smaller channel. Good quality long term keywords will boost your search impressions if people are searching for what you offer. If you don't bother with keywords, you're taking away one area for potential impessions, in which case search is only relying on your title along. I feel multiple good keywords gives you multiple chances to show up in search results, which gives you extra chances to have your thumbnail seen and clicked, which then boosts your chances of getting into recommended if your content is good.
Good keywords won't save a bad video. But good keywords can definitely help a good video be shown to the right people looking for it.
Those who say tags aren't worth the effort, generally speaking, have many thousands, even hundreds of thousands of subscribers and an already established presance meaning they don't NEED to use keywords. Their social proof and titles are enough to show up in recommended and suggested. But if you're smaller, it's harder to be suggested and recommended, which means keywords and tags are really benificial.
You can see the spikes in my traffic after I started improving my keywords (there was an algorithm change in 2018 which followed average view duration, mine has always been low which is why my suggested traffic tanked) but 2018 is when I started taking tags more seriously, going from single word tags, the better tags. then in 2020 I went through more of my older archive of videos, changed the tags, and my search traffic boosted again. I believe this is evidence that it definitely helps.
why would you NOT want those possible impressions that could lead to more views.