Yes, we have Messi, but even though he is the GOAT, he can't be saving our asses every single game. Most of our players are at the end of their careers, it was just a matter of when this would become brutally obvious. Liverpool made it brutally obvious a few hours ago, this is the truth of the matter.
Of course Anfield is a factor, but if we had prime Xavi/Iniesta/Alves, we could never lose 4-0. Not in a million years, we are simply not good enough anymore. Many teams have come to Anfield and got a far better result than 4-0.
As for winning leagues. Liverpool is the only big European club that has not been able to do it, partly due to fluctuations in your performance over the years, partly due to EPL depth in Top 4 (even 6, now) and partly due to bad luck.
But winning leagues is a footnote next to the European Cup. Barcelona, Juventus, PSG, Bayern Munich, and even Man City are all a bunch of losers compared to where you are right now. The European Cup is the pinnacle of World football, even better than the World Cup if you ask me.
Look at United. They have 20 leagues, but only 3 CLs. Look at Juventus, what 35 Scudetti, but only 2 European Cups. Look at us, we have dominated Real Madrid domestically, but we lag badly in CLs. City/Arsenal/Chelsea/Spurs and even United are envious of you. All of Europe, especially us, are now envious of you. This is the truth.