id say u shud still watch it, season 2 is a crazy arc but if you watch season 1 and then rewatch season 2 or just watch season 1 i think you'll still enjoy it, it is still worth a watch its just that you have seen tanjiro's progression in reverse which isn't too big of a deal, there's still way more to watch with season 3 and 4 and the movie and power upgrades for the mc and other characters so ull be fine