Like everything else in life. The answer is "It depends". There is nothing stopping you from learning more with your current job. Regular working hours still leave you with free time on the weekends, and maybe an hour or two every day to read up on stuff you like. Lots of people here, bootstrap a company along with their day jobs. If one's really motivated to learn new things, then status quo is always unsatisfactory…
You are not your job! You can stimulate your mind and learn (and that includes outside of IT too). If you can't get passionate to do that now - you might want to think of how you will cope with challenges as they crop up. Even dream jobs can turn into treadmills after a couple of months.
If the job is not providing enough fodder for your mind to stay alert, it shouldn't actively drain you / make you feel listsless.