Online education isn’t just a good option for students due to the reasons discussed here, as it is also a great opportunity for people interested in tutoring. It isn’t just people who’ve already got a career in teaching who can gain something from this (although experience would be helpful), as so long as you have relevant and desirable skills and expertise, then you have the potential to monetise your knowledge.
Teachers interested in this are preferred for this role, for a number of reasons. Firstly, most of the work revolves around what they should already be familiar with; grading work and teaching people useful techniques for grasping an idea they are familiar with. Most of the tutoring takes place in the context of somebody doing an online course, where they manage their workload and work through the syllabus at their own pace; your role as an educator is generally to review the final products and tutor them on how to improve their work.
Teaching online can pay reasonably well, and is generally a good option for supplementing income from a full time job.