Features? No. If I'm not happy with how a product operates today, I'm not holding out hope for improvement in the future. Buy what it does today, not promises for tomorrow.
Security and Bug Fixes? Not indefinitely, but I would expect the minimum generally accepted consumer warranty protections in modern economies: a year? Two? I'm also happy to help out keeping things up to date, if its open source (not everyone can do that, but not everyone has to, that's the magic of software. and this is HackerNews, not Facebook).
Look, here's the reality: software has changed. You don't just get to charge $10/month, fail to get traction, then cry "people don't want to pay for high quality software, its all these hackernews luddite types who think everything should be open source". Office 365 is $5/mo. Apple's suite is ~free-$2/mo, with a device purchase (Apple Notes is probably the most-used note taking app on the planet). Google Workspace is $6/mo; it could literally just be Keep, it'd be 70% as functional as this product, and nearly half the price; oh, and it comes with the global standard of email inboxes, with a custom domain, global standard calendar provider, a terabyte of file upload, global near-standard office suite... Notion is $4/mo. That's your competition!
Sure, none of them do exactly the same thing; but they're pretty close, and people have an inelastic amount they're willing to stretch their monthly spend beyond these high value services to perfectly hone in on a workflow that works. It's the same kind of inelasticity that keeps Excel wildly popular despite tons of more nuanced competitors.
Here's my expectations, above all else: that in ten years, the data I've given this service will still be accessible, no rug pull, no pivot, no dirty acquisition. That's the trade-off you seem to be forgetting. The biggest risk to the users of most products isn't "paying enough to afford the developers necessary to maintain it and build it out"; it's "charging so much that they never gain traction, and disappear overnight". The way toward alleviating that fear, today, is one of extremes; you can either be a huge megacorp with so much tangential revenue & momentum that a rug pull is unlikely, or you can go the Obsidian.md route, not necessarily open-source but at least open, standards-compliant, useful, locally stored data. This product instead goes the 2010s VC-backed "just build a pretty product and charge a subscription people will come lol" route, and that route is destined for failure.
Or, you can keep complaining that people won't pay for software. In an era where more money is spent on software than at any other point in computing history. People pay for software. That's the problem. So, figure it out, or die; but don't blame consumers because you've got a suicide wish to be customers' 22nd subscription service that's marginally different than two others they already pay for.