And here is some other thing like that.

Yeah, but those aren't Jira alternatives to start with, as they don't compete in the same target market.

But plenty of people/companies in the target market of the simpler tools end up using Jira anyway.

This is like objecting to a fairly lightweight orchestration tool calling itself a 'Kubernetes alternative' - it is an alternative, it won't necessarily fulfil all needs of everyone using Kubernetes (resp. Jira), but it will for a lot of them, a lot of them don't need everything it's offering anyway. Of course they're going to use one of the most well-known players to paint the picture of what sort of thing the product is.