Hello. While what Reddit is doing isn't great, it's the reality of running a site that's now owned by venture capital to make some kind of economic return for its owners. Running a site like that isn't free, and advertising dollars alone are probably not enough to generate the sort of return that its owners are looking for (or even pay for the its costs).
The core issue is twofold: Big Tech has devalued online services to the point where users are inured to not paying for them, and because of this inurement, most users are unwilling to pay for most online services if they don't seem to be offering a value add. Gaming services like Steam have managed to get their users to pay but that's because they are offering a service that's generally superior to piracy, such as immediate downloads, achievements, and other online services. But no one is ever going to pay to use a message board, and I doubt gimmicks like Reddit Gold bring in much money.
Perhaps the future is found in the past - people migrating back to self-hosted message boards - there used to be thousands of these back in the 1990s and 2000s. Some of them were run as small businesses, others were run as hobbyist projects by their owners. But I doubt there's going to be a mass exodus, and unfortunately, centralization has increasingly become the norm for the Internet.