Chelsea were in 4 different comps last season and he was playing as part of their second squad in those. I don't begrudge him going to Chelsea to play with the manager who got the best out of him and being at a club which had a chance of being in the CL. It was worth the shot to try and push on as a player. It's no shame either to not have got ahead of Enzo and Caicedo.
You seem to have a really high threshold as to what is good enough for Everton, a team that finished 13th last season and a team that's going to be starting with James Garner in midfield at this rate. That's a low benchmark yet you're setting the benchmark very high for some reason. In the midfield names that have been suggested here or we have been linked with id rather have Luiz > KDGH > Brownhill, but I think a player of Luiz's ilk is going to be hard for us to attract. I think we need two anyway and Luiz and KDH would be a good two to go for, they'd both upgrade us instantly.