is a "technical" scrum master a non-negotiable requirement for organizations nowadays?

The Scrum Master role is extensive. Looking at what the Scrum Guide says, I'd say that the Scrum Master is involved in:

• Leading and coaching the organization in the adoption of agile methods, including but not limited to Scrum.
• Coaching the Scrum Team on techniques and practices to self-organize and self-manage.
• Maximize the productivity of the Scrum Team.
• Teach the team techniques for achieving the Definition of Done and evolving the Definition of Done over time.
• Coach the Product Owner on effective techniques for product management, including listening to the voice of the customer, managing requirements, scoping and defining products, building roadmaps and schedules in a manner consistent with empiricism, and more.
• Ensuring that everyone on the Scrum Team understands the Product Goals and Product Backlog.
• Facilitate Scrum Events.
• Finding and teaching techniques for creating and maintaining the Product Backlog, including communicating the Product Backlog to stakeholders.
• Facilitate communication and collaboration between the Scrum Team and external stakeholders
• Ensure that impediments are removed, either by direct action or by coaching.

To achieve all of these, one would need expertise in agile and lean methods (including beyond the Scrum framework), teaching, mentoring, facilitation, technical expertise in the Developers' domain, business and product management, and organizational behavior. It's improbable that one person will have all of those strengths, so organizations need to look at what problems they have and find people with the skills to help them solve those problems. In my experience, though, it's hard for an organization to know what skills they don't have and need if they have never had those skills in the first place.

Something else I've noticed is that "Scrum Master" is often a team-level role. Aside from cases where the team is working with other teams or parts of the organization, organizations put the Scrum Master in a position to work with development teams directly. They may have other roles that fill needs at a higher level. SAFe provides a good example of this - product management really happens at the Solution Train Engineer and Release Train Engineer levels, and SAFe Program Consultants work at the Enterprise level and across portfolios or programs.

Personally, I believe that there are places for people from non-technical backgrounds as Scrum Masters. They may not help the team learn about domain-specific tools, technologies, and practices to maximize productivity. Depending on their background, however, they could be in a good position to emphasize facilitation and improving interactions or communication.

Another problem could be awful job descriptions.

I found that most of these offers are dedicated for technical scrum masters or half time scrum masters who can fill the position of a lead developer at the same time. I know that the scrum guide did not specify anything about having a scrum master as a full time job. but doesn't this create some kind of hierarchy within the scrum team?

Having a "lead developer" position would, and you could try your luck explaining this. Agile coaching is part of a Scrum Master's job, and both may begin and end at interview.

In truth many organizations are not after a Scrum Master at all, who would shine a light on such things, but a salve to cover the organization's problems.

Well, it is often said that being a Scrum Master for one Scrum Team is not a 100% job. if the team matures, the Scrum Master has less to do and could take over additional teams. and there are Scrum Masters that work with several teams.

So in HR people tend to forget the maturity level and expect that a SM can take care of several teams right from the start or could be SM and Developer at the same time. That can work, but depending on the maturity level, the SM may need more time as the SM and got less time as member of the Development Team. With that knowledge, it seems strange to have the SM starting as SM and Lead Developer at the same time (ignoring the fact that this would add hierarchy to the DevTeam).

I would support that the Scrum Master should have at least some knowledge about the development and domain of the product, to fully support DevTeam and PO. But the focus should be on Scrum.