Design consideration for MetroE network. Would you place Layer3 switches for the connection points?

Hello I have a client that is installing a Metro E network and wants to use Layer3 switches (Arista) as the backbone for the sites. How common is that?

Maybe I'm old but I always separate switching from routing so I would only consider a traditional router for each of the sites' connection point with a L3switch as the next hop inside. Is my perspective too old fashioned or rigid?