It is boring on so many levels. AI is useless and no challenge even with its massive bonuses at higher levels.
This is amplified by the fact you aren't ever really competing against the AI so the fact it has massive bonuses means nothing as it can never actually get ahead in any meaningful fashion.
I have read the defense of the legacy path system which says they are guidance and what you will be doing anyway, which I think is the only reason the AI actually managed to do any of them at all.
The leaders and civs are bland and not actually many of them. We apparently have hundreds of possible combinations to add variety which is just marketing spin to hide the small number and then as you keep changing civs you don't feel any attachment to them.
There is actually very little design or content with essentially just re-skins from previous eras. The only era with any real changes (the last era) is over before you get to see/use/unlock many of them.
Maps are always predictable and the same, seemingly as a consequence of the DL mechanic.
I complete epic/huge/long era games it the time I would beat quick games in previous versions so you quickly have seen and done everything.
As I have mentioned in other posts ,once I knew what was doing i found myself doing exactly the same thing in every game no matter what leader/civ/victory/difficulty i was playing with the only real difference being as I realised how easy and no-brainer the game is I even stopped trying to optimise as I could wipe the floor with the game by just cruising, even on diety.
There was no more to see, no more challenge, no more improvement, no more optimisation or better strategies to work out...what is the point in improving when it is already a walk in the park.