Blockbase was created as a “universal” parent theme. The aim of universal themes was to help us the transition from Classic themes to Block themes, while the Site Editor was still in development. Blockbase was instrumental in helping us make this transition.
Universal themes inevitably make some compromises to make it possible to customize them using Classic theme tools. Block themes on the other hand are becoming more powerful as more features are added to Gutenberg.
At the same time, the Site Editor is becoming a more mature tool and consequently, the value of Universal themes is diminishing. Consequently Blockbase no longer offers the same benefits as it once did.
The utility of parent Block themes depends on your use case. In many situations it is not necessary or even optimal to use a parent theme at all.
As for the future of Blockbase, we don’t anticipate making any significant changes to this theme, but we are committed to maintaining it for the foreseeable future.