In 1956 JRRT wrote the following (quoted by CT in the intro to Lost Tales 1):
...I do not think it would have the appeal of L.R. - no hobbits! Full of mythology and elvishness, and all that 'heigh stile' (as Chaucer might say), which has been so little to the taste of many reviewers.
So the answer is quite obviously a resounding "yes" - but with the caveat that what Tolkien was describing was the unpublished Silmarillion as it existed at that time.
The published Silmarillion is a combination of sources ranging from the 1937 Quenta Silmarillion (with the ending chapters taken from the earlier Quenta Noldorinwa), subsequent revisions, the last versions of the Annals of Aman and of Beleriand (both of which a surprisingly large amount of text comes from), the independent "mini-works" (Ainulindale, Valaquenta, Akallabeth, Rings of Power) and some later essays, together with some editorial work and independent invention by CT.
Given that so much of this material already existed at the time JRRT wrote that letter (a lot of it dates to the period between the completion and publication of LotR), and that so much of it was intended for inclusion in the Silmarillion (e.g. the Annals as appendices), it can be reasonably argued that the comments made in the letter are valid for that too.
So it's a "yes".