I'm afraid I don't agree. I have both the BPI-R2, based on the MT7623 which is a 1.4GHz ARM Cortex-A7 (successor to the A9) board, and the BPI-R64, based on the Mt7622 which is a 1.35GHz ARM Cortex-A53 board. The 64-bit A53 board gets almost exactly twice the integer performance per core as the 32-bit board, at essentially the same clock frequency.
My version of OpenWrt does. For example...
...Wireguard on Linux uses the existing crypto-api, which makes use of NEON. From lsmod on my BPI-R64:
chacha_neon 20480 1 libchacha20poly1305
poly1305_neon 20480 1 libchacha20poly1305
Also wireguard isn't the only new generation of crypto being used. For example, I use Syncthing on my main router as the hub for all my devices' file sync. Syncthing uses several primitives, including AES and chacha20, which both see a major boost on the A53.
The A9 is not a poor CPU. I use my MT7623-based device as a client bridge in my office, and it is also a decent little file server for my LAN. But single-core performance is important, as generally this will be the rate-limiting link due to interrupt handling. And at twice the performance-per-megahertz, my main house router's A53 is a major asset.
In any case, I think this discussion may be a little distracting for the OP.