I think the series is starting to crumble under its own weight. The core idea of the game was always to offer as much freedom, content and game modes as possible. But there comes a point when it's just too much. It becomes too much for the devs to adequately fine tune and adjust all the content, expectations from players become too high, and the game just becomes a bit too unfocused. What was once the game's biggest asset (content) is now a bit of a dead weight holding it down. You kinda have to feel for Playground Games a bit, because this idea is what made the game what it is today, helped it grow to this huge player base. It's gotta be hard to go back on it now, especially with Microsoft breathing down your neck, asking you to help boost the gamepass numbers.
FH5 has an insame amount of game modes when you think about it, from all different race types, to online modes, PG games, eliminator... And yet none of them feel completely polished. The car list is absolutely massive and incredibly varied, compared to literally any other car game, but still fans feel disappointed not to see enough new cars. And the cars added don't feel that special IMO, they're not really given the proper presentation and care to shine as they should. It just feels like a new collectible. The map kinda has the same issue IMO, it's bigger than ever, but because they wanted to have as many biomes as possible, all the biomes end up fairly small, which makes the map feel a bit too fragmented.
The frankly unacceptable amount of bugs at launch probably has a lot to do with this as well.
I've been thinking about the Festival playlist and I think there could be an interim way to kinda nudge the game in that direction. Making the Playlist less "tasting menu" and more "single player career". It's a bit of a shame to build a car for a PR stunt, and then just forget about it. The playlist isn't very engaging when it just feels like a list of chores to get through. If the series were more car focused, with car themes, and championships, stunts, modes, and especially rewards that all fit within the same car theme, it'd help bring the focus back on the cars. Maybe making people choose a car and stick with for a big part of the playlist, building and tuning it for different events, spending more time with a car, could help cars to feel more special. This series' World Cup is kinda a step in the right direction but it's still fairly timid. I think they should have forced people to choose a country and you'd have to stick with it for the whole series.
It's kinda frustrating because all the ingredients for a great game are there already, and I do enjoy the game a lot. It's not like it is particularly lacking in any way, it just needs to be rearranged and structured a bit better IMO. I hope GT7's likely success gives PG some ideas about single player structure. And they maybe cut back some of the content for FH6, bring a bit more focus to the series.