I agree with most of what you’re saying, but not the last paragraph.
FH4 and FH5 are very similar in the development stages → bugged release, first big update after a few months, 2 DLCs, and a last bigger update before the game gets minimal support until next title. Overall a stable and finished game after 2 years
FH3 was really the last FH from the last generation, I like to mark it as: FH1 - 1st gen; FH2 & FH3 - 2nd gen; FH4 & FH5 - 3rd gen.
The reason is that with FH4 the Horizon Series has gotten a lot of changes - longer development stage and support, more bigger updates. While FH1, 2 & 3 had 1 to 2 DLCs, FH4 & 5 had at least 2 + big updates, eg. FH4 = the festival playlist and later the eliminator or FH5 = the anti lag and physics/effects that came with Rally Adventure and later EventLab 2.0.
The way the Horizon games have being developed has changed, but not only to the worse, how it’s portrayed by many YouTubers. It is true that over the years Microsoft has put more stress on the developer studios (T10 & PGG), but the studios themselves have done an amazing job at keeping the games running. My main concern is time, the CEOs want to bring the games out asap before investors loose interest, but the studios can’t deliver that fast. I mean there is a reason why GTA6 needs 10 years and not 2 or 3, and will probably be delayed too. The latest FM is really a new standard of disappointment, eg. no new features less content than ever. But before FM, the series has always been pretty good at balancing quality and content quantity. From FM4 to 5 there was a lot of content lost, but quality went up and with FM6 & 7 they delivered more content sadly though never reached the extent of FM4’s Eventlist.
The way that the Horizon series evolved when talking about game play aspects was not bad. EventLab, Eliminator + 2.0, graphics, car sounds, map size, physics (specifically off road).
There are also downsides to that, like a very minimalist story line, not updated car models, recycled content and some other things people subjectively find bad.
And neutral things that get criticized, like road width, eg. the widest roads in any Horizon are in FH2 in Nizza/Nice, but nobody ever talks about those 2 lane old town roads that could house 6 lanes. Or the engine sounds in FH3 which are over 90% synthesized, but there are people that think those are better than FH5, I’m just going to claim that this is objectively wrong… lol.
I also think Motorsport and Horizon should be criticized more separately, because PGG is a British developer studio and therefore has different working environment and freedoms than T10 in the US, which might be one of the reasons FH does better than FM. PGG is also a lot bigger in employee count. Microsoft still has the same say about release dates which is a huge problem, but not about studio internal structures so much.
Imo, the only “real” problem that Horizon has, is the bad decisions about release dates and minimal to non game testing before release. If PGG never were part of Microsoft they would probably deliver more complete games, but also less. Of course ignoring that without Microsoft they would have never gotten the license for “Forza”. (as a side note: the devs who quit PGG a few months ago will probably release a pretty stable and finished The Crew and Forza Horizon competitor in a few years, assuming they are not under some release date contracts.)
As a note at the end:
I never really played FH4 because I only listened to negative criticism at that time and even though I experienced near to no bugs, the game didn’t do it for me. Half a year before FH5 came out I started playing FH4 weekly and realized how much progress there was made since launch. It finally felt like the game was worth 80 bucks. I would really suggest you to get into FH5, since launch the game has delivered so much free content, even if you don’t buy the car packs and car pass or expansions, there is so many things you just can’t do/experience in previous titles.
Sorry for the long comment, I just think this debate is very biased. It’s ok to not like the game and not play the game, but don’t focus on the bad things exclusively. The Horizon series has come a far way. I’m still hugely concerned for Motorsport after the latest title released.