What is more valuable vulnerability to chase ?

Hello everyone i just have a generic question i am at a cross-roads on what vulnerability to chase after or should i be well-rounded. Here are the vulnerabilities i am chasing in the real world on platforms that offer bounties and so on. I know i will get many opinions and so on but these days which is worth it and would be the most challenging and less competitive. Thank you for any input or advise i really appreciate it.

**- SQL Injection **
**- Command Injection **
- Cross Site Scripting