$5 includes a generous free tier for Workers KV that can hold upto 10MiB of data against a single key. Cloudflare does not charge for bandwidth consumed, I believe. Also, use of Cloudflare's zonal http-cache is free.
I guess, when I compared, I took Lambda@Edge's per second billing into consideration and not per 50ms (which brings down the RAM usage cost from $62.52 to $3.13 and total usage from $68.52 to $9.13).
What really sealed the deal for me was the very low cold-start times with Workers. I'm not aware of recent improvements with Lambda@Edge, but the last time I tried them, it wasn't uncommon to hit 100ms+ start times.