FritzBox is way better than isp-provided or TP-Link-like boxes but certainly not pro-anything (no vlans or ingress-qos, guest-wifi but no real multi-ssid, severely limited dns-customization ...)
fritzboxes are everything but certainly no "prosumer"-type devices. Most of their "mesh" is still dual band. only the latest repeater "FRITZ!Repeater 3000" is tri-band and afaik there is no router yet available that supports tri-band.