There was once a series with a well-structured formula and, most importantly, a consistent lore where you could connect all the dots and get a larger picture from it.
For better or worse, the rigid structure of gyms, evil team and Elite Four succeeded by a Champion was what made Pokémon, "Pokémon". Like many games of its kind, when you got a Pokémon game, you knew what you were getting into. Furthermore, every addition to the lore was an addition rather than a replacement. Many things were only loosely connected, but you could get something that mostly made sense and, as new additions were incorporated to the lore, they did not exclude what was old and already existed. Rather, these retcons weren't so drastic as to completely negate what came before, but gave new meaning to already existing elements.
Fast forward to ORAS.
In ORAS, the character of Zinnia was introduced and with her came the multiple timelines story. That was a game changer because, up until that moment, every addition to the Pokémon timeline was linear. We were supposed to assume that each pair of games took place later than the one before it. The Hoenn remakes broke that logic by establishing that a new timeline was introduced with X and Y and ORAS was a part of that new timeline. The reason for my sig is simple: ORAS' "jump the shark" moment is because the old timeline was made obsolete as it lacked Mega Evolutions and for all we knew the new path was going to feature more and more Megas. It felt like the old games were worthless.
Then Sun/Moon came and what happened was a complete makeover. They discarded the whole structure of a Pokémon game that was familiar to the fans, in favor of so-called "Trials" that are pretty standard practice in other RPGs. Another addition that was brought up in Sun/Moon was the Alolan Forms, which go against what has been set in stone in Pokémon lore, as changes based on adaptation to the environment was the characteristic of one single Pokémon (Eevee), and occasionally others like Wormadam, for whom the explanation was distinct and convincing. On top of that, the Alolan Forms seem to be designed with "superior" types/stats in relation to the metagame and their classic counterparts, which makes their goal obvious - to replace the now obsolete classic forms which barely anybody uses anymore. Finally, the introduction of uncatchable Ultra Beasts breaks the classic logic from Pokémon that each boss is only as good as the Pokémon they can form a team with, and every Pokémon you see in the game is obtainable one way or another.
And, to complete the trainwreck, the announcement that Megas will be banned from the next VGC means that the developers of the games are probably no longer interested in a mechanic that everyone made a huge deal of and which was pivotal to the generation immediately preceding this one. This created an extreme inconsistency and confusion as to whether Megas would be seen again and which will be their place now that they could be phased out and whether the new timeline will see its conclusion. It sounds to me that the Pokémon team does not know in which direction to take the games (the sales of which are in decline) and is creating mechanic after mechanic without any concern for balance and systematics. This could mean that in 8th gen the Z-Crystals are replaced with yet another object and yet another mechanic and disappear without any explanation as to why.
My disillusion with the Pokémon series, therefore, stems from this lack of consistency. We buy Pokémon games because we want to play Pokémon games. If I wanted to play dungeon crawlers with a completely messed up timeline I'd get Zelda instead. It's no secret that Pokémon has been stale for a while, but IMO transforming it and its monsters into something they're not, is not the path to take and does not do any good for the series especially in its 20th anniversary, when the old games should've been paid homage to instead of effectively neglected.
