20K a month is a decent SEO budget.
Hard to know without site details and keyword list.
Hopefully your total digital marketing budget is greater than 20K.
Don’t have your eggs all in one marketing basket.
Using my 27 years of SEO experience.
I can tell you that relying on “free” traffic from Google is NOT a Solid long term business plan.
There is a graveyard of businesses who relied on free Google traffic.
It is much safer to have a holistic approach to digital marketing.
A business can no longer think of SEO, PPC and Social Media as marketing channels in isolation.
That’s my 2 cents