I find the Standard meta-game to be a thrilling puzzle to solve. However, it’s just one of many contexts that can let you feel the thrill of outsmarting your friends. Casual decks are usually less expensive. A good Standard deck could cost $150-$300. Then, in a year or two, those cards rotate out and typically lose some of their resale value. For some, this isn’t sensible, and for others, it’s not fun.
Or, perhaps you just prefer the flavor of an older group of cards. For instance, Angel decks are ridiculously popular. Statistically, the majority of players are not concerned with grinding it out in a coherent format — they’re just playing with whatever cards they happen to have. Which, of course, is why you buy them!
There may still be benefits to aligning of chronology even when anything goes. For one thing, each block (which is a group of 2-3 sets) has its own crop of mechanics — common strengths found on numerous cards — which usually synergize well with each other. So if you are using creatures from 2010, there may be advantages to also using lands and spells from that era. It’s possible.
Secondly, if your friend uses cards from that era, it’s likely that the other cards from then have special ways to deal with those. For instance, in a set with lots of dragons there was a creature, Dragon Hunter, who had protection from dragons. So, the interactions you find may be not only powerful, but potentially also unusual and fun (and it’s usually not as “on-the-nose” as “protection from dragons” - Magic generally tries to be more vague). Formats are designed to be somewhat swingy; to give you a chance to stabilize against great odds if you draw the right sequence of cards. This usually won’t be a problem, but in some cases, if your cards are from dramatically different pools or eras, you might have matches that feel less engaged, where your spells talk past each other rather than grappling directly.
To be sure, the mechanics of Magic are generally broad and can engage each other in many, many ways, so it’s completely possible to have a thrilling duel even if you’re using cards that were not designed to face each other. I’m just saying, that not only has the game gone through ups and downs, but it has also gone through phases where some strategies were juiced in a way that was hard to interact with. If you’re planning to play kitchen table Magic, and your deck is too powerful, it may be less fun — because it’s not only winning that’s fun; it’s winning a fair fight that’s the most fun. (Also, keep in mind that the cards you have from years ago might simply be too weak, and you should look around at what else to use).
If you want your match-up with a friend’s deck to be really fun, here are a couple things to consider. First, consider using a color or combination of colors that they are not, so that you can try to sneak around them rather than just butting heads. Consider using cards from the same year, or roughly the same era, so that the art matches (and the mechanics will). Third, have a mix of creatures, removal spells, a way to draw extra cards, a way to protect or strengthen your creatures, and possibly a non-land way to generate mana.
Most of all, if you can tell that your opponents are not having fun, or if you are not, try to address the problem. Try a different deck, or ask for help from the Internet or your local card store. Finally, remember that not everyone understands the rules completely and in more casual environments, you may be up against a friend who has been doing something incorrectly for years. You can usually find the answer to any rules question online, if you’re not sure.