Combination of roles PM + BA + Tester. Is it worth it?

Question

Project management

Hello! I recently got a job in a company as a project manager, where, in addition to management, I have to perform a fairly wide range of duties:
1. Technical writing
2. Testing
3. API design
5. Testing

I am trying to convince the manager that appropriate specialists are needed for these duties (analyst and tester ), but the manager claims that such a situation is normal.

Tell us how PMs work in other companies and do all PMs now perform such a wide range of duties

Answer 1

As in a particular company it is organized so for it and the norms. Whether it suits you or not is another question.
In general, of course, blurring responsibilities or working outside of your skill set or contractual arrangements is much more often a minus than a plus. But it happens that people, on the contrary, expand their area of ​​responsibility for various reasons.
Judging by the question, this is not your case and such a situation does not suit you - so there is another question - what to do.