The staggering rise of mental health issues across the globe, with anxiety disorders leading the charge, calls for innovative, accessible and effective solutions. Enter the era of online therapy, a boon for our technologically intertwined lives. With a focus on anxiety disorders, one can discern the immense potential of online therapy, not merely as a stop-gap arrangement, but as a dynamic and evolving treatment modality. Let us explore the four compelling reasons which underscore the indispensability of online therapy for anxiety.

Firstly, accessibility is the cornerstone of online therapy. The logistics of traditional therapy sessions can prove daunting for those living in remote areas or for those with disabilities. In the absence of geographical limitations, online therapy democratizes mental health care. This egalitarian approach is not only inclusive but also disrupts the conventional paradigm of therapy being an urban, privileged pursuit. Just as our forebears harnessed the power of the printing press to disseminate knowledge, we now have the digital platform to make therapy accessible to all.

The second compelling factor is convenience. With our lives operating at an accelerated pace, time management is of the essence. The necessity of commuting to a therapist's office might deter potential therapy seekers. Online therapy circumvents this by offering flexible scheduling options. It is akin to the economic principle of reducing transaction costs to enhance market efficiency. By reducing the 'transaction cost' in the form of time and effort spent in travel, online therapy increases the efficiency and effectiveness of mental health care delivery.

Thirdly, anonymity provided by online therapy can be a significant incentive. The stigma associated with mental health continues to persist, discouraging many from seeking help. In this context, online therapy provides a safe and anonymous space for individuals to seek help without fear of judgement or social repercussions. This is reminiscent of John Stuart Mill's Harm Principle, which champions individual liberty, allowing people to do what they wish without societal interference, as long as it does not harm others. Online therapy embodies this principle by providing an unprejudiced platform where individuals can freely express themselves and seek help.

Lastly, online therapy capitalizes on the ubiquity of technology in our lives. The proliferation of smartphones and internet connectivity has enabled seamless integration of therapy into our digital lifestyles. A study by the Pew Research Center has revealed that 96% of Americans own a cellphone of some kind, with 81% owning a smartphone. Leveraging this, online therapy creates an omnipresent support system, enabling immediate help at times of crisis. In essence, it is the application of Just-In-Time principle, a methodology used in supply chain management to reduce lead time, here used to provide therapy exactly when needed, thereby enhancing its effectiveness.

However, like any other solution, online therapy comes with its limitations. Notably, the absence of face-to-face interaction can lead to lack of complete understanding or misinterpretation. This is akin to the Heisenberg's Uncertainty Principle in quantum mechanics, where one can never simultaneously know the exact position and momentum of a particle. In therapy, the therapist might face the same conundrum, struggling to understand the exact emotional state of a patient without a physical interaction.

Despite these limitations, the potential of online therapy for anxiety disorders is undeniable. As we grapple with the challenges posed by mental health issues, it is incumbent upon us to explore and adopt solutions that are accessible, convenient, stigma-free, and tech-based. By harnessing technology and aligning it with the principles of economics, ethics and supply chain management, online therapy seeks not just to manage, but truly revolutionize mental health care.