Just how popular is Yorushika in Japan?

I know they’re quite popular (from Youtube views, Spotify streams, Anime OPs and the surprising amount of Yorushika-related fanarts I found on Twitter and Pinterest) but are they top tier popular? Is their music considered mainstream there? What do we know about the Japanese fandom?

I’m currently in the EU and I’ve met a couple of Japanese students (on separate occasions) and while they all know Yorushika, they only know one/two very popular songs at most (Itte and DakaBoku), and one was actually surprised that Yorushika is rather known overseas. Though I’m aware that the sample population is way too low to draw any conclusions.

I also firmly believe that any Japanese art form that becomes popular overseas will inevitably have two completely distinct fandoms with two completely different general vibes due to the language barrier, so I just thought it’d be interesting to know.

Disclaimer: this is genuinely out of curiosity, I have zero intentions of turning this into a popularity contest or gatekeeping-related post.