Understanding politics that way is common and understandable. It's also an unfortunate cultural construction of the term, because this understanding is deeply incorrect.
Politics is what happens when people disagree about what should be done, or how it should be done. That's it. That's what politics is.
There are principled and corrupt reasons for disagreement. There are forthright and deceptive/manipulative means of engaging disagreement. All of that is politics.
When someone is advocating for a better PTO policy either because they personally would like something more advantageous for themselves or because they think it'll boost morale and productivity, that's politics.
When someone manages their office relationships to increase their chances or being hired into a higher management position either because they personally would like to advance their career or because they think they can help the business run more effectively, that's politics.
When someone attempts to spoil management on tech stack X and talk up tech stack Y, that's politics whether it's because they know both well and are sure which will suit the business & problem domain better, or because their personal expertise is more with Y than X and it'll increase their value to the organization without further investment.
The problem with assuming "politics" refers to inherently underhanded activity is that it shirks the work of engaging disagreement productively and instead pathologizes disagreement in one way or another -- usually by either pathologizing an opposing position or class of people.