That didn‘t work so much for Dynalist.
Looks like it's still alive and kicking. I guess you're probably upset by a lack of updates or something - luckily upgrading to a paid plan would be a good way to incentivize whoever is developing it to continue working on it, at least at the margin.
What you missed is that the paid offer didn‘t stop the developers to lose interest and… start Obsidian!
Subscriptions do motivate ongoing development, but only if there's a threat to stop going or start incurring subscriber losses. Product software categories have different ratios of customers who buy subscriptions for the current utility vs the investment into future utility.