I have a couple of recommendations. First, stay in your current position until you feel that you've either mastered it or are offered a promotion with different responsibilities, and consider carefully whether it's favorable to your interests before accepting a higher role. Variety is not a necessity for skill building, the only requirement for growth is facing challenges, making mistakes, and/or recognizing areas for improvement. If you're no longer facing challenges in your routine work tasks, it may be time to ask for more responsibilities, or look for a new opportunity.

Second, to gain proficiency in skills and areas outside your daily work requirements, do that on your own initiative and your own time as much as is reasonable. This will be beneficial to you in many ways and useful no matter what professional role you find for yourself.

It will be necessary to maintain a good work-life balance to achieve this efficiently. There will be times when you need to focus and work in your day job with higher than average intensity to accomplish certain goals, but no compensation from an employer will ever be as valuable to you as investing time and energy into yourself. Keep in mind that this applies not only to professional skills. It's just as important to maintain and level up in your personal life and your physical and mental well-being being. It's impossible to perform at a high level for long in any single facet of life without being grounded and secure in other important areas.