SEO is not right for every business, and I say that as someone who makes his living doing SEO. If you just started your business, you just launched your website, and you need to get leads now, you should not be investing the majority of your marketing budget in SEO. For a business like that that doesn't yet have an established brand.
You're gonna get half the benefits of SEO by just doing the basics, setting up your Google Business Profile and doing some basic optimizations on your website. But spending 15 to 2000 dollars a month on SEO just is not worth it for a business like that. If you're on a budget and you need to get leads now, you're gonna have way more success with Google Ads or Facebook ads.
On the other hand, if you're an established brand with a big website and you've never done SEO before, you should be investing in that like now. These are my favourite companies to work for almost every time. We can easily 2 x or 10 x their traffic.
So just be aware of that if you're a new business, especially if you're talking to SEO agencies, they're all gonna tell you you need this big SEO plan. But if you're on a budget and you need leads now, please look into Google Ads or Meta ads.