I don’t think the liturgical practice in the Oriental Orthodox churches is meaningless at all. It requires humility on the part of the bishop; pride is toxic to bishops and monastics, and most of our bishops are also monastics. The function of the liturgy is to demonstrate the greatest serving the least to the congregation, to inspire piety in the youths whose feet are washed (also historically, in churches in the deserts of Syria, Iraq and Egypt and the beautiful but rugged countryside of Armenia and Lebanon, to relieve real discomfort in preparation for Pascha), and to remind the bishop of his role by forcing him to humble himself as Christ did.
The Eastern Orthodox version is less moving in my personal opinion, but still meaningful. This is one of those cases where the OO managed to get an edge on us liturgically (another being the lovely variable fractions of the Coptic Rite, the colorful vesture of the Syriac Orthodox Rite and, theoretically, the diversity of West Syriac anaphorae, and also the longer Coptic and Ethiopian liturgies, which maintain superb quality despite an increase in quantity).
Also historically Western Christians would give alms on Maundy Thursday in lieu of foot washing, which would not have at the time been meaningless.
However those restorationist churches in which everyone washes everyone else’s feet quarterly before the Eucharist has been celebrated have I think overdone it.