It is also a cloud-based service that artificially limits what you can do for pricing, not a standalone desktop app. No thanks, I will resist buying into those for as long as I can.
Be it web or offline, does not really change as both flash and rive are proprietary software. I think rive is still better as its runtimes are open source and the export format is documented https://help.rive.app/runtimes/advanced_topics/format so technically you could make your own editor.
At least your produced rive content could be kept online / shown in your software as the runtimes are open source. Meanwhile flash has been reversed for ages and ruffle still isn't 100% compatible. Adobe being adobe, they are even worse as they aren't web app, but still contain heavy online DRM making the software useless if you don't have subscription, in addition to their cancelation terms being very shady.