This may not be helpful…I don’t use either, but I know the 10k is well structured and beyond just a vocab list with sentence add ons and audio and such with alot of community feedback to tune it which is really ideal for vocab SRS while the JLPT is deck is straight up vocab and less filter options & tag options.
I’d say it’s a personal decision and would probably factor your short term goals and other study methods you are using. Though the 10k is exceptional, a reason I don’t use it is because I like the autonomy of various difficulty levels in various decks where I can choose what I want to review daily and not obligated to review it if I don’t want to (which is important to my study style). Sometimes I review certain content just to refresh and I’m not obligated to SRS it daily. Other larger decks with harder content, I have to review daily otherwise the SRS will smash me (which is ok, that is exactly what I want). And I’m not necessarily recommending this approach, it’s just what works for me.
I think I had enough through the WK experience to constantly get land-locked-content; both lesson/review without any choice and for me that wasn’t very motivating and review count had to be cleared daily (but then again, some others like it). Of course the 10k has far more flexibility than that and many here have benefited greatly…with the ‘known’ vocab features in Kitsun, I likely will selectively use the 10k myself eventually (which is another option and a benefit of the Kitsun platform to have a collected base of all your known words and then deck-jump anywhere you want).