It isn't really Pokémon that has changed as you say, it's more that the appeal of Pokémon has grown so vastly and in such a varied way. Many people view and use Pokémon in the same way you do, with an emotional (and probably nostalgic) connection to childhood, but many other people are drawn to it for other reasons - to me, Pokémon was similarly valuable to my childhood as an escape. It was also and introduction to the wider culture of gaming.
However, it is also sometimes just a tool to decompress with at the end of the day. A fun, get-up-and-go game to distract myself while dinner is in the oven. Other people draw pleasure from it purely through competitive battling. And why shouldn't they?
I echo Kieran's point - in Smogon,
competitiveness is the name of the game. Of course people would suggest how to improve your team - that is their goal, after all.
I don't think the fact that people enjoy Pokémon for such disparate reasons is really a bad thing.
Im not trying to sound like a crotchety old man, but Pokemon is a series I hold dear to me and right now its like watching someone you love die in front of you... Pokemon Gold helped me through alot of tough times as a child, alot of abuse and stuff... so I take things like this very seriously...
I would urge you to take a lighter view. Pokémon is not dying in front of you. It is one of the most celebrated and unifying forces in the gaming world today. Look at us now, speaking across countries about it.
Recognise that your experience of Pokémon is not equal to everyone else's, that every individual may make their own connection to it and take pleasure of it in whatever capacity - and that makes it all the more wonderful.