Yes, for simple polls. The quickest method needs nothing installed: post your question with the options, add an emoji for each option as a reaction, and let people vote by clicking. It works well for fast, informal decisions. Slack's Questions and Custom Poll features also let you build a poll without a third-party tool.
The limits show up quickly. Emoji polls have no anonymity, no scheduling and no open-text answers. If you need any of those, or you want results collected properly, that's the point to look at an app like Polly or Simple Poll — the /poll command requires the Polls app to be active.