>>536155803
First of all, I'm a SEAnigger, so I play OCG, and it's way, way cheaper than TCG, which is why it's way easier to keep up with the game.

>I really wanted yugioh to be a bigger part of my life after returning, but I'm 30 and I'm realizing in the past 2 years that it really can't.
If it couldn't, then don't force it, something will be a bigger part of your life naturally.
If you really like YGO then it will matter a lot to you over time, otherwise let it be a fun side thing you do sometimes.

>Do you just casually show up with the same few decks with some upgrades every day, maybe play MD casually on the side?
From my experience, half of the locals are usually people playing random shit, so I just play whatever deck I want, although I really only play deck casually, for tourneys I play my better decks.

>How often and what level of decks do you buy and on what criteria?
I just buy/play whatever I want, some decks are sitting in my room unused

>I got fucked by like 80-90€ boxes
Don't buy boxes if you want to play the game, buy boxes if you want to open boxes and don't care about the return

>I'm starting to think just showing up every week or every other week that I get to go is the majority of my enjoyment.
I mean, yeah, the social part is typically a big part of the enjoyment, sometimes I came to just hang out with my friends and barely playing, and that's fine too.

>I also seriously question if I need meta decks
Having one would be nice if you feel like being a tryhard sometimes, but if you rarely use it might be a waste of money once KoA hits it unless you have the money to burn.

I'm also in my early 30s, we're at the age where we can't really be too lax in life and yet if we don't relax we will collapse.
Like the other anon said, just play for fun, so just play YGO they way you want to play it; if you want to be a tryhard then be one, if you want to be a casual then be one, if you want to be both alternatively then just do it.