All of them have something going on. 1 The horror vibe/2the bombastic story (prescot's speech)/G3 brothers till the end.... Judgement the visuals and overrun. G4 my least favourite game of the main series.
Gears 5 is the best one in my opinion. The amount of content is insane (even when some will complain their fav character has not made it into the game yet).
The future is hard to say because TC is working on a new ip first.
G6 could be like Halo infinite becoming free to play with modes/campaign locked behind a payment.