In Jain Dharma, mukhpatti is used not mainly as a medical filter, but as an ahimsa practice.

Why mukhpatti is used:

• It helps reduce the chance of inhaling or harming tiny living beings in the air.
• It also prevents droplets from the mouth from reaching others or the environment.
• It supports careful speech and mindful conduct, especially in pratikraman, samayik, swadhyay, and temple use.

Why not just a good modern mask?

• A modern mask is usually made for medical protection, not specifically for Jain non-violence discipline.
• Mukhpatti is traditionally designed to be light, simple, and suitable for continuous mindful use.
• In Jain practice, the object itself is not the only thing; the intention and observance of ahimsa are also important.

So, from a Jain viewpoint, mukhpatti is used because it is a symbol and tool of restraint, reverence, and non-violence, not merely a face covering.