I think one of the problems we have nowadays is that there are more clubs who are our equal or better than us than there used to be. And that makes things harder!
In the good ol' days of Moyes the Premier League had a top 4. After that there was Spurs and us and maybe A Villa. That was it. That's who we competed with.
The last 10 years has seen the emergence of Man City, Leicester, Southampton, Burnley and Wolves who all are/or have been arguably on a par or better than us at one time or another.
So we are no longer competing for 5th-7th spots with 2 or 3 clubs we are up against many more, all with the same ambitions as us.
This emergence of clubs has made the Premier League more interesting for the neutrals but a lot harder to consistently cement a top 6 (European) place.
Hopefully under Moshiri (and Usmanov) the money will keep rolling in for us and we will continuously buy in better players which will ultimately give us the edge over our rivals. And Ancelotti will weave his magic and turn us into a much better team.
Otherwise I think the struggle continues.