It must be different demographics: in here everyone watches WEC for the prototypes. And the big names like Valentino Rossi or Alonso when he did the Toyota stint, obviously, no matter what class they are driving in.
LMP2 is something for connaisseurs, GT3 are like "people not able to drive a proto but with cars that manufacturers have to field anyway and bring up numbers".
Also, if you want to see proper GT3, at least in here, you watch Fanatec GT World Challenge Europe (which is often deemed with stronger drivers than the ones in WEC or IMSA - although now there's a quite big overlap).
Last year of GTE in WEC saw an epic battle among Ben Keating and the Iron Dames, I personally loved it... but everyone was sure that both teams would have barely made regular top 10 finishes in SRO due to the higher pool of talents in the GT3-only series.
At least now many SRO talents have switched to WEC.
In comparison look at IMSA entry list: 11 LMDh, 13 LMP2 and 32 GT3 among GTD Pro and GTD.
That to me is like old "on the verge of closing down" endurance series where almost no proto were racing - not even a dozen cars. [and no, no one gives a damn about P2 - although some cheers are given for Spike or United Autosport - proper proto = hypercars in the mind of fans]
EDIT: almost forgot, there are fans of DTM - deprecated by veteran fans because they do race GT3 cars and not the useless Class 1 vehicles of old - and British GT (which is a national mix of GT3 and GT4 on the grid together - Italian GT, which is nothing on par, run a similar mix, with GT3 and GT Challenge/Cup/Trofeo cars together).