Will WebGL work for this build?

We are just starting out on our project. We are getting warnings from some folks saying our game won’t run smoothly in WebGL because it is graphic heavy. Its a sample of this: Fantasy Dungeon Ossuary | 3D Dungeons | Unity Asset Store
and
Neon City Complete Pack | 3D Urban | Unity Asset Store
Is this true about WebGL?
if so, what is the alternative for online game play?

HDRP is not supported in WebGL
You can use the URP instead. But yes, it looks different → Will SRP ever be usable for webGL?