I think you assume more than just what you stated.
You are assuming that Gerald Everett isn't going to make more of a difference to our new offense than the top wide receiver drafted at that point.
We could have had Zay Jones/JuJu Smith-Schuster and some others there.
You are assuming that an OL we could have drafted there would be better than what we already have on our roster.
We also could have had Lamp there at G (maybe C)
But McVay, when faced with these choices, chose Everett.I guess he thinks Everett was the best receiver (tight or wide) on the board
Our OL coach feels what he has to work with is better than what was available in this weak choice of OL prospects.