I had a fritzbox 7530 and switched to a MikroTik in frustration. I wanted to do dev for the network, so my motivations were strong.
Home routers seem to struggle though. Fritzbox have a number of mentions in this thread too, which doesn’t surprise. Mine struggled for sure.
I do now have both routers still and I’ve also done some benchmarking with the MikroTik connected too: Performance testing upload/download using sn_httpd. Maybe related to QUIC window size
If we want something definitive, I could potentially switch the old fritz.box back in an run the same tests. I suspect the differences would be pronounced.