Right in the article they are discussing adding ads and premium subscriptions features in the future.

I can already see the timeline for BlueSky over the next few years:

• Receive startup venture capital
• Provide a useful, user-friendly service
• Grow a userbase <-- (you are here)
• Add a few more useful features, continue growing
• Dominate the market, run at a loss
• Add less useful features like ads, premium features, subscriptions
• People complain, but most are too hooked in to leave
• The useful features added earlier start getting removed, content gets sanitized <-- (Imgur, Reddit is here)
• Big fundraising campaign, IPO, or bought out by big corp or the melon husk of the day.
• Content quality goes way downhill, actively making life harder for users, volunteers and staff, bots rampant, more stupid features, monetization monetization monetization <-- (Twitter is here)
• People leave for another useful, user-friendly service