also on your point of more expensive cogs being better, it's pretty common practice with big road teams to use lower spec cassettes and chains to bring the bikes up to UCI weight limit. Which they obviously wouldn't do if it had any effect of the actual workings of the drivechain
We are talking 1/8 chains and fixed cogs. The cogs are constantly with the chain. A cassette has different cogs that get different amounts of action on the chain. Different altogether.
also on your point of more expensive cogs being better, it's pretty common practice with big road teams to use lower spec cassettes and chains to bring the bikes up to UCI weight limit. Which they obviously wouldn't do if it had any effect of the actual workings of the drivechain