Yes

> Give Plausible Analytics a try Plausible Analytics is built with simplicity, speed and privacy in mind. We’ve used Google Analytics for years and understand its pitfalls

It’s an ad but not a hidden/submarine one. It’s a blog post on the company’s blog giving a long list of reasons to try their product instead of their major competitor.

Yeah, this article was submitted by a SaaS marketing expert: https://markosaric.com/

There are some misleading parts of the article, which makes it even worse (e.g. by default Google uses the data from GA to profile users).

Yes, but you really have to read the whole thing to see it. Even then, they listed their own product last on a list of alternatives. I equate it to how Privacy Badger approached their product (although it's free): your privacy is compromised, so try their product which will protect your privacy. This type of "honorable" advertising is OK in my book.