が数多く

many

→ が
phrase Rare #39,901
many が marks the subject, while 数多く means “in great numbers.” This phrase often appears with verbs such as ある, いる, or 出てくる.
JA: この町には古い建物が数多く残っている。
EN: Many old buildings remain in this town.

象徴が数多く出て来るがこれは最悪だ

A lot of symbols appear, but this is the worst.

— 8 1/2 (1963)

今日、私たちに考えるべき社会問題が数多くある。

Today, there are many social issues for us to think about.

古いインドの伝説が数多くある。

There are many old Indian legends.

金銭に換算できないものが数多くある。

There are many things that cannot be measured in monetary terms.