For new projects, avoid classic themes entirely – they’re a legacy approach that doesn’t provide the benefits of modern WordPress development. Focus your energy on learning block theme development for all new work.
Existing classic themes should be maintained with classic approaches unless you have compelling reasons to change. Don’t add block features to working classic themes without strong justification – the complexity isn’t worth the effort.
Hybrid themes create more problems than they solve when transitioning from classic to block approaches. The two systems don’t integrate well, leading to unpredictable issues that are difficult to troubleshoot and resolve.
Instead, start with block themes and add classic fallbacks only when necessary. This approach provides standardized development patterns, builds your block theme expertise, and creates reusable solutions for edge cases.