Should I build a Slack community?

There are so many places to connect with potential customers. Discord, Telegram, Slack, Reddit, Twitter, etc.
Ultimately, it depends on where your customers are and how it helps you connect with them. I use Discord as a support channel for Finclout users.

If you're considering building a Slack community, there are a few things you should keep in mind. First, Slack can be a great way to build and foster a sense of community among your members. However, it's important to make sure that your community members are active and engaged, otherwise the community will fizzle out quickly.
Another thing to consider is whether or not you have the time and resources to Moderate a Slack community. Slack communities can be quite active, and if you're not able to keep up with the conversations, it can be frustrating for members.
Finally, you should think about what kind of content and discussions you want to have in your Slack community.

Slack.

We have a slack community for senja.io where people share their questions and give us feedback. Even though it's really small it's fairly active. Not sure it would have started growing as quickly with Telegram.

For traction, I still think a community with slack is a good option. I know I'd join.

Newsletter is enough but it doesn't hurt to have slack or discord

Good idea for building a community! I'm not sure whether Slack or Telegram is the right choice. I think it depends on your users and what kind of lifestyle or habits they might have.

For me, I built a Discord community to support users in their routines and provide a place for bugs and feedback. It worked great and it's became a place for all of us to connect and share some of our lives.

So I definitely think building a community for your product is a good idea! I would say it's a good idea to identify what you want members to discuss and the purpose of the general channel. Too many or too little purposes can create disorganization and ultimately lead to lack of engagement.