I was using this but immediately saw the writing on the wall as soon as the Composition API came out with its far superior typescript support. Converted our greenfield Vue 2 app over to the new API within a few weeks which turned out to be the correct decision.
Unfortunately, unless you were following Vue development very closely this would've slid by.
Are you sure vue-class-component 8.0.0 RC1 doesn't work? I see it was in development for v3 before being discontinued.