Looking at https://data-star.dev/reference/datastar_pro#pro-features the features that stood out for me as things I would want to to use (and that don't feel particularly "pro" to me) are the animation features, data-replace-url, data-on-resize, data-scroll-into-view, the @clipboard() mechanism and, most importantly, the debugging tool.
My problem with this business model is that it has a chilling effect on open source contributions to the project, because it incentivizes the core maintainers to not accept community contributions that overlap with the paid features.
Datastar is currently in the Release Candidate phase of v1, which they seem to be certain will be the final form of Datastar. So, they're really not looking for "community contributions" to the core of datastar, other than for feedback to polish it off.
Moreover, ALL of the features are "plugins" - there's nothing stopping anyone from building and sharing their own. It is actually encouraged. In fact, in their next release they'll be releasing and documenting some sort of public API for plugins. Not sure exactly how it will differ from the current form though, since you can already make your own plugins.
They also intend to have some sort of free, open-source "marketplace" for community-built web components, based on their upcoming Rocket web component and Stellar css framework. You would just need to have the Datastar pro license to be able to use any of them.
I can see how this final part might be criticized, but it does seem quite fair to me. Sustainable open source is a big problem - in recent months ive had some important fully-open source dependencies disappear - even ones that were backed by well-funded companies. Moreover, Datastar is registered as a 501c3, and they really don't intend to "make money" from all of this. Its just to pay the bills, travel to conferences etc...
They're very reasonable people and open to all discussion in their discord. Im sure that whatever concerns you still have could be explained quickly if you went there.
In fact, i just posted there about this thread and how its overflowing with nonsensical complaints about how there's no link to or mention of Pro on the homepage - they said sure, we'll add a link.
Naming things really is hard. I can’t even with these names.
what's wrong with the names? they seem perfectly fine to me...
Also, btw, some of these - specifically data-replace-url - are strongly discouraged by the devs, to avoid footguns. I dont have experience with it, but people have spoken lots in their discord about how things like Hotwire Turbo are too magical and end up causing a lot of issues. Datastar strong recommends just using hypermedia as it was designed (HATEOAS https://htmx.org/essays/hateoas/) and doing full page reloads when you change a page. And for more ephemeral in-page changes, you can use the sse fragments morphing etc