The reason the Obi202 has its ethernet pass-through feature is so that it can be installed between modem and router, to ensure that voice always gets prioritized over other traffic, so that other Internet use doesn't scramble voice calls.
Of course, that's most important on slow Internet connections, because they are more likely to run out of bandwidth. If your Internet speeds are less than about 30 mbps, the Obi202 is a very good solution.
But it would be a very useful upgrade of the Obi202 to make an "Obi202+" with gigabit ethernet ports, to keep up with modern, high-speed Internet connections. As it is, to use an Obi202 as it is intended to be used (between the modem and router), on an internet connection faster than about 30 mbps, imposes an unacceptable performance penalty.