PO role getting pushed onto developers

it feels like it is a complete violation of the spirit of scrum

It isn't a violation of the "spirit" of Scrum.   It simply isn't Scrum at all, regardless of whatever labels they wish to slap on the new process.

You can't have Scrum without an effective PO that represents the end-user's interests (customer, internal business department, etc).

Having a PO as part of the Development Team is an inherent conflict of interest.

And blaming their lack of commitment to Scrum on it being "complicated", or on their lack of story design experience, is a very poor excuse.

"being PO and finding out what is needed is complicated / technical job" - of course it is complicated, but not always due to technical reasons, sometimes it is more about understanding and managing various stakeholders.

"Also the real power (budget, what must be done, ...) is now usually in the hands of the scrum master, who also fills a management role." - WHAT MUST BE DONE part is definitely a PO responsibility... Seems like there is a lot of confusion in your company around understanding Scrum...

Is this kind of approach normal or common in the industry now? To me it feels like it is a complete violation of the spirit of scrum. Do you think there is anything I could do?

Yes it is common, yes it is a complete violation of Scrum, yes there is something you can do about it. The first step in adopting an agile way-of-working is to put transparency in place over issues such as this, focusing on how they inhibit the delivery of Done, integrated, release-quality work each Sprint. Where there are antipatterns, identify them. Where there is a deficit for release, expose it. Where sponsorship for change is dubious, question it.

It’s up to those holding power if they wish to do anything about the situation, but you can at least provide essential transparency. Bear in mind however that this is not necessarily something which they are going to appreciate.

Bear in mind however that this is not necessarily something which they are going to appreciate.

This is so very true Ian.   One of the most difficult responsibilities of a Scrum Master is elevating and making visible organizational and/or process issues that many would prefer stay buried.

It isn't a pleasant feeling, but I often feel that my suggestions and observations go over like a lead balloon.   I need to continually tell myself that raising (and continuing to raise) such observations is simply part of my role.

Perhaps Scrum isn't the Agile implementation they want. 

DSDM may be the way to go. It has more roles, a project manager with some authority, business sponsors who can be the PO but not be exactly like the PO in Scrum, and a defined support team. It still has the Development Team (Called Solution Development Team) but breaks it out a little more. For businesses that are uneasy with Scrum and its simplicity, a more robust Agile system may be the way to go.

If they are unwilling to fully adopt Scrum, they may want to consider something more in line with what they actually want. Scrum kind of needs a PO to work. Another Agile framework could allow the role to be split up a bit so it won't require more dedicated people and let some of the people only be partially involved. They aren't as simple to understand as Scrum.

DSDM also has a defined role for the SDT team leader. Scrum has become a buzzword. Companies then want it because they think it will solve all their problems, then they don't want to follow it; causing more problems. A lot of companies could benefit from learning the other Agile methods out there that may be easier for them to adapt to; giving them Agile more in line with their goals.