The verdict
For measuring a site, I'd pick Plausible. It is easy enough that everyone reads it, and it answers where traffic comes from and what converts. It cannot tell you which company visited, and it has no sales features.
I'd add Leadinfo when you sell to businesses, have steady traffic and can follow up quickly. It does not replace analytics. It sits on top of the visits and turns some of them into leads. Leadinfo has no free plan and charges by identified companies, while Plausible follows pageviews. If you have low traffic, or buyers who are consumers or home workers, Leadinfo will identify little, and Plausible alone is enough.