Viability of SEO for a small bootstrapped company developing digital marketing tools

Hi, I work with a small bootstrapped startup developing a digital marketing platform for small and local businesses.

The keywords that we target are also targeted by the thousands of digital marketing agencies around the world (and other software companies in the space) who are constantly generating content and making it very difficult to rank for any of these keywords.

We have not had any real success with SEO so far except for some particular keywords that are low value and are thus bringing us low value users who will never pay for our product. We are not ranking highly for any keywords relevant to our core value.

We are also not looking to provide local services so we are not targeting more accessible keywords such as keywords for particular locations (cities etc).

We are mainly software developers and not SEO experts and wonder if focusing on SEO is worth the effort considering it is unlikely we will be able to get to page 1 for any of our keywords. Or is this wrong?

The main reason I am posting is I spoke to a marketing company recently and mentioned this and they tended to agree and used an example of an (apparently well known) SEO expert who doesn't focus on SEO for his own business for the same reason.

Should we continue trying to improve SEO or would be better focusing elsewhere?